research article synthesis of gold nanoparticles capped...

Research ArticleSynthesis of Gold Nanoparticles Capped with Quaterthiophenefor Transistor and Resistor Memory Devices

Mai Ha Hoang1 Toan Thanh Dao2 Nguyen Thi Thu Trang3

Phuong Hoai Nam Nguyen4 and Trinh Tung Ngo1

1 Institute of Chemistry Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Cau Giay Hanoi Vietnam2Faculty of Electrical-Electronic Engineering University of Transport and Communications No 3 Cau Giay Street Dong DaHanoi Vietnam3Institute for Tropical Technology Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Cau Giay Hanoi Vietnam4Faculty of Engineering Physics and Nano-Technology University of Engineering and Technology Vietnam National University144 XuanThuy Cau Giay Hanoi Vietnam

Correspondence should be addressed to Mai Ha Hoang hoangmaihaichvastvn

Received 28 October 2015 Revised 4 December 2015 Accepted 24 December 2015

Academic Editor Ahmed Mourran

Copyright copy 2016 Mai Ha Hoang et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Recently the fabrication of nonvolatile memory devices based on gold nanoparticles has been intensively investigated In thiswork we report on the design and synthesis of new semiconducting quaterthiophene incorporating hexyl thiol group (4TT) Goldnanoparticles capped with 4TT (4TTG) were prepared in a two-phase liquid-liquid system These nanoparticles have diametersin the range 2ndash6 nm and are well dispersed in the poly(3-hexylthiophene) (P3HT) host matrix The intermolecular interactionbetween 4TT and P3HT could enhance the charge-transport between gold nanoparticles and P3HT Transfer curve of transistormemory device made of 4TTGP3HT hybrid film exhibited significant current hysteresis probably arising from the energy levelbarrier at 4TTGP3HT interface Additionally the polymer memory resistor structure with an active layer consisting of 4TTG andP3HT displayed a remarkable electrical bistable behavior

1 Introduction

The synthesis and characterization of gold nanoparticles havebeen intensively investigated because of their numerous pos-sible applications in physics chemistry biology and mate-rial science [1ndash3] Recently there have been many reportsregarding the fabrication of electronic and optoelectronicdevices using gold nanoparticles (AuNPs) A large numberof approaches have been developed to prepare AuNPs usingdifferent ligands such as alkanethiols phosphines aminesand polymers [4ndash6] Unfortunately these ligands often hin-der the charge transport as a dielectric layer on the surfaceof AuNPs Therefore the use of conjugated oligomers orpolymers to protect AuNPs is of particular interest for themodulation of charge transfer and optical properties of thesenanoparticles [7ndash9] However these AuNPs generally showedrelatively poor dispersion in organic solvents that weakenedtheir potential application in solution processing

AuNPs have been embedded into120587-conjugated host poly-mers to produce nanocomposites that combine the uniqueproperties of AuNPs and 120587-conjugated polymers [10ndash15]For solution processable fabrication P3HT is one of themost widely used polymers because of its excellent proper-ties [16 17] In this work we prepared gold nanoparticlescapped with quaterthiophene by a simple solution processingtechnique These nanoparticles have a good solubility inorganic solvents and are well dispersed in the host polymersThe intermolecular interaction between 4TT and P3HT wasexpected to improve the charge transport between AuNP andthe conjugated polymer The presence of 4TTG in P3HThost matrix dramatically influences the thin film transistor(TFT) memory device characteristics We also fabricateda nonvolatile memory resistor based on P3HT and 4TTGwhere P3HT serves both as matrix and active component ofthe device

Hindawi Publishing CorporationJournal of ChemistryVolume 2016 Article ID 1247175 8 pageshttpdxdoiorg10115520161247175

2 Journal of Chemistry

2 Experimental Procedure

21 Materials All commercially available starting materialsand solvents were purchased from Aldrich TCI and AcrosCo and usedwithout further purification All of the reactionsand manipulations were carried out under N

2with standard

inertatmosphere and Schlenk techniques unless otherwisenoted Solvents used in inertatmosphere reactions weredried using standard procedures Flash column chromatog-raphy was carried out with 230ndash400 mesh silica-gel fromAldrich using wet-packing method P3HT was purchasedfrom Sigma-Aldrich The 221015840-bithiophene 1 5-dodecyl-221015840-bithiophene 4 and 2-(51015840-dodecyl-221015840-bithiophen-5-yl)-4455-tetramethyl-132-dioxaborolane 5 were prepared accord-ing to the modified literature procedures [18]

22 Synthesis

5-(6-Bromohexyl)-221015840-bithiophene 2 A solution of bithio-phene 1 (249 g 015mol) in 300mL tetrahydrofuran (THF)was cooled to minus78∘C in an acetonedry ice bath N-Butyllithium (016mol 64mL 25M in hexane) was addedthrough a syringe over 10min The temperature of the reac-tion mixture was slowly raised to minus30∘C and was maintainedfor 1 h After that the reaction mixture was cooled againto minus78∘C and 16-dibromohexane (1464 g) was added viasyringe The mixture was stirred for 30min at minus78∘C andthe bath was then removed the solution was stirred for anadditional 3 h while the temperature was increased slowlyto room temperature The reaction mixture was next pouredinto 500mL of dichloromethane (DCM) and 200mL of 1MNH4Cl solution The organic phase was separated washed

with water dried over sodium sulfate and concentratedThe residue was crystallized with methanol to remove 16-dibromohexane The resultant precipitate was purified withsilica-gel column chromatography using chloroformhexane(150 vv) and then crystallized in methanol to afford 256 gof solid yield 52

1H-NMR (300MHz CDCl3) 120575(ppm) 716 (dd 1198691= 52Hz 119869

2

= 16Hz 1H) 709 (dd 1198691= 40Hz 119869

2= 16Hz 1H) 698 (d J

= 40Hz 1H) 694 (d J = 40Hz 1H) 667 (d J = 40Hz 1H)342 (t 2H) 279 (t 2H) 186 (m 2H) 169 (m 2H) 137ndash151(m 4H)

5-Bromo-51015840-(6-bromohexyl)-221015840-bithiophene 3 A solutionof 5-(6-bromohexyl)-221015840-bithiophene 2 (92 g 28mmol) in150mLDCMwas cooled to 0∘CN-Bromosuccinimide (NBS53 g 30mmol) was added The mixture was stirred at roomtemperature overnightThen 200mL water was added to thereaction mixture The organic phase was separated washedwith water dried over sodium sulfate and concentrated Theresidue was purified with silica-gel column chromatographyusing hexane to afford 943 g of colorless oil yield 83

1H-NMR (300MHz CDCl3) 120575(ppm) 694 (d J = 40Hz 1H)691 (d J = 40Hz 1H) 683 (d J = 40Hz 1H) 667 (d J =

40Hz 1H) 341 (t 2H) 279 (t 2H) 187 (m 2H) 169 (m2H) 137ndash151 (m 4H)

5-Dodecyl-51015840-(6-bromohexyl)-221015840-quaterthiophene 6 5-Bromo-51015840-(6-bromohexyl)-221015840-bithiophene 3 (322 g7mmol) 2-(51015840-dodecyl-221015840-bithiophen-5-yl)-4455-tetram-ethyl-132-dioxaborolane 5 (284 g 7mmol) and tetrakis(triphenylphosphine) palladium (230mg 02mmol) weredissolved in 50mL of toluene under an argon atmosphereThe resultant mixture was stirred at room temperaturefor 5min before an aqueous K

2CO3solution (15mL 2M)

was added The mixture was stirred for 24 h at 90∘C undernitrogen Then the mixture was cooled down to roomtemperature and neutralized with 1M HCl solution Theorganic layer was separated and the aqueous phase wasextracted with DCM The combined organic layer wascondensed and the residue was purified with silica-gelcolumn chromatography using chloroformhexane (15 vv)to afford 301 g of yellow solid yield 65

1H-NMR (300MHz CDCl3) 120575(ppm) 704 (d J = 40Hz 2H)699 (d J = 40Hz 2H) 697 (d J = 40Hz 2H) 669 (m 2H)342 (t 2H) 276ndash283 (m 4H) 185ndash190 (m 2H) 165ndash173(m 4H) 126ndash147 (m 22H) 088 (t 3H)

Anal Calcd for C34H45BrS4 C 6170 H 685 Br 1207 S1938 Found C 6178 H 675 Br 1209 S 1935MS (MALDI-TOF)119898119911 [M]+ Calcd for C

34H45BrS4 66189 found 6621

5-Dodecyl-51015840 -(6-ethanethioatehexyl)-221015840 -quaterthiophene7 A solution of 5-dodecyl-51015840-(6-bromohexyl)-221015840-qua-terthiophene 6 (199 g 3mmol) and potassium thioacetate(068 g 6mmol) in 100mL NN-dimethylformamide wasstirred at 90∘C overnight Then the mixture was cooleddown to room temperature and 100mL water was added tothe reaction mixture The resultant precipitate was filteredand washed with methanol and then purified with silica-gelcolumn chromatography using chloroformhexane (11 vv)After that it was crystallized in THFmethanol to afford 171 gof yellow solid yield 87

1H-NMR (300MHz CDCl3) 120575(ppm) 703 (d J = 40Hz 2H)699 (d J = 40Hz 2H) 697 (d J = 40Hz 2H) 668 (m2H) 287 (t 2H) 279 (t 4H) 233 (s 3H) 166ndash170 (m 6H)126ndash142 (m 22H) 088 (t 3H)

Anal Calcd for C36H48OS5 C 6580 H 736 O 243 S 2440Found C 6577 H 742 S 2432 MS (MALDI-TOF) 119898119911[M]+ Calcd for C

36H48OS5 65709 found 65720

5-Dodecyl-51015840-(6-thiolhexyl)-221015840-quaterthiophene 4TT 5-Dodecyl-51015840-(6-ethanethioatehexyl)-221015840-quaterthiophene 7(151 g 23mmol) was dissolved in 100mL THF A solutionof potassium hydroxide (028 g 5mmol) in 5mL ethanolwas added and the mixture was stirred at room temperatureovernight Then 200mL of water was added slowly toprecipitate out the product The resultant precipitate was

Journal of Chemistry 3

filtered and washed with methanol and then purified withsilica-gel column chromatography using chloroform Afterthat it was crystallized in DCMmethanol to afford 13 g ofyellow solid yield 92

1H-NMR (300MHz CDCl3) 120575(ppm) 703 (d J = 40Hz 2H)699 (d J = 40Hz 2H) 697 (d J = 40Hz 2H) 668 (m2H) 277ndash281 (m 4H) 250ndash256 (m 2H) 161ndash171 (m 6H)126ndash144 (m 22H) 088 (t 3H)

13C-NMR (100MHz CDCl3) 120575(ppm) 14567 14525 1367213659 13537 13527 13453 13440 12492 12483 1240012359 12335 3388 3192 3159 3141 3019 3007 29642936 2907 2845 2805 2460 2270 1415

Anal Calcd for C34H46S5 C 6639 H 754 S 2607 Found C6635 H 742 S 2618 MS (MALDI-TOF)119898119911 [M]+ Calcdfor C34H46S5 61505 found 61520

Synthesis of Gold Nanoparticles Capped with Quaterthiophene4TTG An aqueous solution of hydrogen tetrachloroaurate(60mL 0015M) was mixed with a solution of tetraoctylam-monium bromide in toluene (80mL 005M)The two-phasemixture was vigorously stirred until all the tetrachloroauratewas transferred into the organic layer and the color changedto orange 4TT (018 g 03mmol) in 60mL toluene was thenadded to the organic phase The mixture was stirred at 70∘Cfor 1 hThen the mixture was cooled down to room tempera-ture and an aqueous solution of sodium borohydride (50mL02M) was slowly added with vigorous stirring After furtherstirring for 6 h the organic phase was separated washed withwater dried over sodium sulfate and concentrated Finally4TTGwas precipitated in DCMacetonitrile to afford 03 g ofdark brown solid


Elemental Analysis Au 6402C 2378H 261 S 959

23 Instrumentation 1H NMR spectra were recorded on aVarian AS400 (399937MHz for 1H and 100573MHz for13C) spectrometer 1H chemical shifts are referenced to theproton resonance resulting from protic residue in deuteratedsolvent and 13C chemical shift recorded downfield in ppmrelative to the carbon resonance of the deuterated solventsMALDI-TOF analysis was performed on a Voyager-DE STRMALDI-TOF mass spectrometer The elemental analyses formeasuring the composition of C H S andNwere performedon an EA1112 (Thermo Electron Corp West Chester PAUSA) elemental analyzer Thermal properties were studiedon a TGA50 (Heating rate of 5∘Cmin) All transmissionelectronmicroscopy (TEM) images were obtained at 200 keVwith LaB6 filament using a Tecnai G2 F20 S-Twin andrecordedwith a 2Ktimes 2K pixel resolutionVeleta TEM camera

(Olympus) on Cu TEM grids Absorption and emissionspectra were obtained using an HP-8453 spectrophotometer(photodiode array type) and Hitachi F-7000 fluorescencespectrophotometer using quartz cells respectivelyThe redoxproperties of 4TT and P3HT molecules were examinedusing cyclic voltammetry (CV EA161 eDAQ) The electrolytesolution employed was 010M tetrabutylammonium hexaflu-orophosphate (Bu

4NPF6) in a freshly driedMCTheAgAgCl

and Pt wire (05mm in diameter) electrodes were used as thereference and counter electrode respectively The scan ratewas 50mVs Atomic Force Microscopy (AFM AdvancedScanning Probe Microscope XE-100 PSIA) operating in thetapping mode with a silicon cantilever (type A resonantfrequency 150 kHz) was used to characterize the surfacemorphologies of the thin film samples

24 TFT Memory Fabrication To study charge transportproperties of the 4TTGP3HT blend bottom-gatetop-contact (BGTC)TFTdevice structurewas employedThegateelectrode was n-type doped ⟨100⟩ silicon wafer and the SiO

2

gate insulator has a thickness of 300 nm The substrate wascleaned thoroughly by a series of ultrasonications in differentsolvents such as acetone cleaning agent deionized waterand isopropanol The cleaned substrates were dried undervacuum at 120∘C for 1 h and then treated with UVozone for20min Then the wafers were immersed in a 8mmolL solu-tion of n-octyltrichlorosilane (OTS) in anhydrous toluenefor 30min to generate a hydrophobic insulator surface Theactive layer (4TTGP3HT 19) was deposited on the OTS-treated substrates by spin-coating polymer solutions (1) at1500 rpm for 40 s Finally the source and drain electrodeswere prepared using thermal evaporation of gold (100 nm)through a shadow mask with a channel width of 1500 120583mand a channel length of 100 120583m Transfer characteristics ofthe devices were determined in air using a Keithley 4200 SCSsemiconductor parameter analyzer

25 Resistor Memory Device Fabrication The memorydevices were fabricated according to the modified literatureprocedures [15 17] The first step involved preparation ofthe substrate Glass substrates were cleaned with detergentdeionized water acetone and isopropyl alcohol in an ultra-sonic bathThe substrates were dried for 2 h and subsequentlytreated with UV ozone for 20min After that the bottomaluminum (Al) electrode was deposited by using a thermalevaporator with a shadow metal mask at a base pressure of2 times 10minus6 torr The UV-ozone treatment was repeated again toactivate the Al surface The active layer of 50 nm was formedby spin coating a solution of 09 wt P3HT and 01 wt4TTG Finally the top Al electrode was deposited Both theelectrodes have a thickness of 70 nm The device had an areaof 2 times 2mm2 The electrical characteristics of the devicewere also measured using Keithley 4200-SCS semiconductorcharacterization system under ambient conditions

3 Results and Discussions

31 Synthesis We report the easy high-yield synthesis of newsemiconducting quaterthiophene 4TT incorporating hexyl


4TT

SS

SS

SS

SS

SS

SS

SS

SS

Br

Br

Br

BrBrBr

Br SS

BO

O

SS

SSS

H

NBS

BuLi

BuLi

BuLi

KOH

OB

OO

1

2

3

4

5

6

7

H3COCS

KSCOCH3

Pd(PPh3)4Na2CO3

+

Scheme 1 Synthetic route of 4TT

thiol group In comparison with reported quaterthiopheneanalogues [19ndash22] this compound bears two long alkyl chainsthat could improve its solubility In Scheme 1 the Suzukicoupling reaction of 5-bromo-51015840-(6-bromohexyl)-221015840-bithiophene 3 and 2-(51015840-dodecyl-221015840-bithiophen-5-yl)-4455-tetramethyl-132-dioxaborolane 5 was conducted inthe presence of a catalytic amount of tetrakis(triphenyl-phosphine) palladium to afford compound 6 Thiscompound was converted to compound 7 After removingthe ethanethioate group 4TT was obtained in good yield

We prepared gold nanoparticles 4TTG by keeping theconcentration of hydrogen tetrachloroaurate tetraoctylam-moniumbromide and varying the concentration of the ligand4TT (Figure 1(a)) It was found that the mole ratio of 31(Au4TT) was optimum for the formation of AuNPs cappedwith 4TT without the aggregation of nanoparticles

TheNMRof 4TTG and 4TTwas similar which indicatedthat AuNPs were capped with 4TT Elemental analysis gavethe following Au 6402 C 2378 H 261 S 959The C H S ratios of 4TTG and 4TT were similar further

confirming the formation of 4TT layer on the AuNPsThermogravimetric analysis (TGA) showed that the 4TTGstarted losingmass at about 265∘CTheweight loss from roomtemperature to 800∘C was about 35 that well matched theelemental analysis result

32 Morphology of QTTG TEM images of the 4TTG(Figure 1(b)) showed that they were narrow polydispersednanoparticles with diameters in the range 2ndash6 nm The nar-row polydispersity of AuNPs could result from the formationof a self-assembled 4TT layer on the growing nuclei In com-parison with dodecanethiol-protected AuNPs the particlessize of 4TTG was bigger It is because of the steric effectthat restricted the interaction between 4TT and the surfaceof AuNPs

33 Optical and Electrochemical Properties The solutionsamples were prepared in chloroform with a concentrationof 1 times 10minus6M and the thin film samples were fabricated


SS

SSS

S SS S

SS

SSS

S

SSS

S

S

SS

SS

S

SSS

S S

SS

SS

S

S

SSS

SSS

SS

S

SS

SS

SS

S SS

S

SS

S

S

S

4TTG

(a)

5nm

20nm(b)

Figure 1 Schematic illustration of self-assembled 4TT layer on the AuNPs (a) and TEM images of 4TTG (b)

(i)(ii)

(iii)(iv)

00

02

04

06

08

10

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

00

02

04

06

08

10

PL in

tens

ity (a

u)

(a)

(i)(ii)

00

02

04

06

08

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

(b)

Figure 2 UV-vis absorption and PL emission spectra (a) UV-vis absorption spectra of 4TT (i) and 4TTG (ii) PL emission spectra of 4TT(iii) and 4TTG (iv) in solution state (b) UV-vis absorption spectra of P3HT (i) and a composite of 10 4TTG in P3HT (ii) in film state

by spin-coating with 1 wt solutions The absorption spec-tra of 4TT and 4TTG in solution state were shown inFigure 2(a) 4TT showed an absorption maximum at 401 nmwhile 4TTG exhibited an absorption maximum at 395 anda shoulder at 500ndash550 nm those were contributed by 4TTand AuNPs respectively This spectrum suggested that theaverage particle size of 4TTG was below 5 nm because largerparticles often exhibit a sharper and more intense plasmonabsorption band close to 525 nm [4] 4TT exhibited PLspectral behavior with emission maxima at 466 and 493 nmin solution state Interestingly the PL spectrum of 4TTGshowed low efficiency due to their self-absorption

The absorption spectra of P3HT and the composite of10 4TTG in P3HT in film state were shown in Figure 2(b)Similar absorption maxima of these films were located at520 nm A slight float was observed in the film state of the

composite which was attributed to the presence of 4TTG inthe matrix The composite also showed a good film formingthat could be used for the device fabrication

CVmeasurements were taken to determine the oxidationpotentials of 4TT and P3HT We combined the oxidationpotential in CV with the optical energy band gap (119864

119892

opt)as determined by the cut-off absorption wavelength in theabsorption spectrum to calculate the lowest unoccupiedmolecular orbital (LUMO) levels 4TT and P3HTwere foundto have the highest occupied molecular orbital (HOMO)levels ofminus518 andminus502 eV respectively Concomitantly 4TTand P3HT have LUMO energy levels of minus252 and minus312 eVrespectively

34 Atomic Force Microscopic Study AFM images of P3HTand the nanocomposite of 10 4TTG in P3HTwere shown in


40minus45

5

4

4

3

32

21

1

0 0

minus4

minus2

0

2

4

(nm

)

(nm

)

(120583m)

(120583m)

(a)

0

5

4

3

2

1

0

5

4

3

2

1minus5

minus25

0

25

5

minus505

(120583m)

(120583m)

(nm

)

(nm

)

(b)

Figure 3 AFM topographic images (5 times 5120583m) of the spin-coated films of P3HT (a) and 4TTGP3HT (b)

Au Au

4TTG P3HT

SiO2

Si+n

(a)

Gate voltage (V)

(1)(2)

(3)(4)

minus60 minus40 minus20 0 20 4010minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

Dra

in cu

rren

t (A

)

(b)

Figure 4 (a) TFT device structure using 4TTGP3HT as active layer and (b) transfer characteristics of the AuP3HTAu (programed (curve(1)) and erased (curve (2)) states) and Au4TTG + P3HTAu (programed (curve (3)) and erased (curve (4)) states) devices

Figure 3 P3HT and the blend of 4TTGP3HTwere dissolvedin chloroform and the resulting solutions were then spin-coated on silicon wafers The surface morphology of P3HTand the blend of 4TTGP3HT thin films exhibited root meansquares (RMS) roughness values of 09 and 12 nm respec-tively The topography of 4TTGP3HT thin films showedsmall surface roughness that indicated a high miscibility of4TTG on the hybrid film

35 TFT Memory Characteristics Figure 4(b) exhibited thetransfer curves of TFT devices with and without 4TTGupon double sweeping where the cyclic sweeping of the gatevoltage was operated from 40V to minus60V and then back to40V These TFT devices showed the p-type characteristics

Transfer curve of neat P3HT film displayed no hysteresis withnear-zero threshold voltage (119881th) By contrast transfer curveof 4TTGP3HT hybrid film exhibited significant currenthysteresis probably arising from the charge trapping effect ofthe 4TTG in the P3HT matrix [10 13] The memory window(Δ119881th) defined as the change in 119881th between programmedand erased characteristics was estimated to be around 20VIndeed charge trappingdetrapping by AuNPs would modu-late the conductivity of the P3HT transistor channel resultingin a change in the transfer curves

36 Resistor Memory Behavior Figure 5(a) shows the resis-tive device structure with a polymer layer sandwichedbetween two aluminum electrodes The active layer consists


Al

Al

Glass substrate

4TTG P3HT

SS

SS

P3HT

(a)

Write

ReadErase

(4)

(1)(2)(3)

minus6 minus5 minus4 minus3 minus2 minus1 0 1 2 3 4 5

Voltage (V)

Curr

ent (

A)

10minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

10minus3

(b)

Figure 5 (a) Device structure and (b) current-voltage (119868-119881) characteristics of the Al4TTG + P3HTAl and AlP3HTAl resistor memorydevices Curves (1) (2) and (3) represent the first second and third bias scans of the Al4TTG + P3HTAl device Curve (4) is the 119868-119881 curveof the AlP3HTAl device

of a P3HT film containing 10 4TTG nanoparticles 4TTGwere selected in this device because gold nanoparticles werecapped with quaterthiophene thiol The quaterthiophene hasa similar structure with P3HT that might lead to an effec-tive intermolecular interaction and charge transfer between4TTG and P3HT

Figure 5(b) shows the current-voltage (119868-119881) curve of thedevice Two distinct conducting states were observed Thepristine device showed a low currentwhen the applied voltagewas from 0 to 25 V which corresponds to the ldquo0rdquo state ofa bistable memory [15 17] When the applied voltage wasapproaching 27 V a remarkably abrupt current increase from2 times 10minus8 to 4 times 10minus5 A was observed (curve (1)) The devicestill remained in the high-conductivity state (on-state) in thesubsequent scan (curve (2)) The onoff current ratio at 1 Vwas obtained to be more than four orders of magnitudeAfter the large applied voltage was removed the on-state stillremained which corresponded to the ldquo1rdquo state of a mem-ory This phenomenon demonstrated a nonvolatile memorybehavior When the applied voltage was reaching minus57 V ahigh-conductivity state returned to the low-conductivity asshown in curve (3) After the device was restored to its low-conductivity state once again it could exhibit a similar 119868-119881characteristic as in the first voltage sweep which indicatedthat the device has a rewritable nonvolatile property On

the other hand the device that used a pure P3HT without4TTG in the active layer did not exhibit a significant currenthysteresis (curve (4)) In this device the 119868-119881 curve stillshowed a low-conductivity state even when the appliedvoltage went as high as 7V For comparison the memorydevice that used P3HT and dodecanethiol-protected AuNPsshowed an ambiguous current jump in off-state and unclearerase behavior [17] This phenomenon could be explained bythe role of quaterthiophene layer of 4TTG Quaterthiophenegroup can interact with P3HT and thereby enhances thecharge-transport between 4TTG and P3HT

4 Conclusion

In conclusion gold nanoparticles capped with quaterthio-phene were successfully prepared in a two-phase liquid-liquid system These particles have diameters in the range2ndash6 nm and are well dispersed in organic solvents Theintermolecular interaction between 4TT and P3HT couldenhance the charge-transport between gold nanoparticlesand the host polymer Transfer curve of TFT device madeof 4TTGP3HT hybrid film exhibited significant currenthysteresis A polymermemory device using P3HT and 4TTGexhibited a repeatable bistable behavior and high stabilityeven after a large number of read-write-erase cycles Four


orders of magnitude difference between the on and off cur-rents was achievedThis report contributes to the preparationof gold nanoparticles for the nonvolatile electronic memory

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This research is funded by Vietnam National Foundationfor Science and Technology Development (NAFOSTED)under Grant no ldquo10402-201367rdquo The authors acknowledgeProfessor Dong Hoon Choi (Korea University) for his kindsupport

References

[1] B Zhang T Cai S Li et al ldquoYolk-shell nanorattles encapsulat-ing a movable Au nanocore in electroactive polyaniline shellsfor flexible memory devicerdquo Journal of Materials Chemistry Cvol 2 no 26 pp 5189ndash5197 2014

[2] P Kannan and S Abraham John ldquoSynthesis ofmercaptothiadia-zole-functionalized gold nanoparticles and their self-assemblyon Au substratesrdquo Nanotechnology vol 19 no 8 Article ID085602 2008

[3] E Boisselier L Salmon J Ruiz and D Astruc ldquoHow to veryefficiently functionalize gold nanoparticles by lsquoclickrsquo chemistryrdquoChemical Communications no 44 pp 5788ndash5790 2008

[4] I Hussain S Graham ZWang et al ldquoSize-controlled synthesisof near-monodisperse gold nanoparticles in the 1ndash4 nm rangeusing polymeric stabilizersrdquo Journal of the American ChemicalSociety vol 127 no 47 pp 16398ndash16399 2005

[5] M BrustMWalker D Bethell D J Schiffrin and RWhymanldquoSynthesis of thiol-derivatised gold nanoparticles in a two-phase liquid-liquid systemrdquo Journal of the Chemical SocietyChemical Communications no 7 pp 801ndash802 1994

[6] X Xu N L Rosi Y Wang F Huo and C A Mirkin ldquoAsym-metric functionalization of gold nanoparticles with oligonu-cleotidesrdquo Journal of the AmericanChemical Society vol 128 no29 pp 9286ndash9287 2006

[7] B Vercelli G Zotti and A Berlin ldquoStar-shaped and linearterthiophene-thiol self-assembled monolayers as scaffolds forgold nanoparticlesrdquo Chemistry of Materials vol 19 no 3 pp443ndash452 2007

[8] B Vercelli G Zotti and A Berlin ldquoGold nanoparticles linkedby pyrrole- and thiophene-based thiols Electrochemical opti-cal and conductive propertiesrdquo Chemistry of Materials vol 20no 2 pp 397ndash412 2008

[9] T Kudernac S J Molen B J Wees and B L Feringa ldquoUni-and bi-directional light-induced switching of diarylethenes ongold nanoparticlesrdquo Chemical Communications pp 3597ndash35992006

[10] H-C Chang C-L Liu and W-C Chen ldquoNonvolatile organicthin film transistor memory devices based on hybrid nanocom-posites of semiconducting polymers gold nanoparticlesrdquo ACSApplied Materials and Interfaces vol 5 no 24 pp 13180ndash131872013

[11] V Suresh D Y Kusuma P S Lee F L Yap M P Srinivasanand S Krishnamoorthy ldquoHierarchically built gold nanoparticle

supercluster arrays as charge storage centers for enhancing theperformance of flash memory devicesrdquo ACS Applied Materialsand Interfaces vol 7 no 1 pp 279ndash286 2015

[12] L Marino S Marino D Wang E Bruno and N ScaramuzzaldquoNonvolatile memory effects in an orthoconic smectic liquidcrystal mixture doped with polymer-capped gold nanoparti-clesrdquo Soft Matter vol 10 no 21 pp 3842ndash3849 2014

[13] Y Zhou S-T Han Z-X Xu andV A L Roy ldquoLow voltage flex-ible nonvolatile memory with gold nanoparticles embedded inpoly(methyl methacrylate)rdquo Nanotechnology vol 23 no 34Article ID 344014 7 pages 2012

[14] D I Son D H Park J B Kim et al ldquoBistable organic memorydevice with gold nanoparticles embedded in a conductingpoly(N-vinylcarbazole) colloids hybridrdquo Journal of PhysicalChemistry C vol 115 no 5 pp 2341ndash2348 2011

[15] H-T Lin Z Pei J-R Chen G-W Hwang J-F Fan andY-J Chan ldquoA new nonvolatile bistable polymer-nanoparticlememory devicerdquo IEEE Electron Device Letters vol 28 no 11 pp951ndash953 2007

[16] H-C Chang C-L Liu and W-C Chen ldquoFlexible nonvolatiletransistor memory devices based on one-dimensional elec-trospun P3HTAu hybrid nanofibersrdquo Advanced FunctionalMaterials vol 23 no 39 pp 4960ndash4968 2013

[17] A Prakash J Ouyang J-L Lin and Y Yang ldquoPolymermemorydevice based on conjugated polymer and gold nanoparticlesrdquoJournal of Applied Physics vol 100 no 5 Article ID 0543092006

[18] S A Ponomarenko E A Tatarinova A M Muzafarov et alldquoStar-shaped oligothiophenes for solution-processible organicelectronics flexible aliphatic spacers approachrdquo Chemistry ofMaterials vol 18 no 17 pp 4101ndash4108 2006

[19] I Barlow S SunG J Leggett andM Turner ldquoSynthesismono-layer formation characterization and nanometer-scale photo-lithographic patterning of conjugated oligomers bearing termi-nal thioacetatesrdquo Langmuir vol 26 no 6 pp 4449ndash4458 2010

[20] H S Kato YMurakami YKiriyama et al ldquoDecay of the excitonin quaterthiophene-terminated alkanethiolate self-assembledmonolayers on Au(111)rdquo The Journal of Physical Chemistry Cvol 119 no 13 pp 7400ndash7407 2015

[21] C Nogues P Lang M R Vilar et al ldquoSAMs functionalised by -quaterthiophene as model for polythiophene graftingrdquo Colloidsand Surfaces A Physicochemical and Engineering Aspects vol198ndash200 pp 577ndash591 2002

[22] R Michalitsch A ElKassmi A Yassar and F Garnier ldquoApractical synthesis of functionalized alkyl-oligothiophenes formolecular self-assemblyrdquo Journal of Heterocyclic Chemistry vol38 no 3 pp 649ndash653 2001

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


2 Experimental Procedure

21 Materials All commercially available starting materialsand solvents were purchased from Aldrich TCI and AcrosCo and usedwithout further purification All of the reactionsand manipulations were carried out under N

2with standard

inertatmosphere and Schlenk techniques unless otherwisenoted Solvents used in inertatmosphere reactions weredried using standard procedures Flash column chromatog-raphy was carried out with 230ndash400 mesh silica-gel fromAldrich using wet-packing method P3HT was purchasedfrom Sigma-Aldrich The 221015840-bithiophene 1 5-dodecyl-221015840-bithiophene 4 and 2-(51015840-dodecyl-221015840-bithiophen-5-yl)-4455-tetramethyl-132-dioxaborolane 5 were prepared accord-ing to the modified literature procedures [18]

22 Synthesis

5-(6-Bromohexyl)-221015840-bithiophene 2 A solution of bithio-phene 1 (249 g 015mol) in 300mL tetrahydrofuran (THF)was cooled to minus78∘C in an acetonedry ice bath N-Butyllithium (016mol 64mL 25M in hexane) was addedthrough a syringe over 10min The temperature of the reac-tion mixture was slowly raised to minus30∘C and was maintainedfor 1 h After that the reaction mixture was cooled againto minus78∘C and 16-dibromohexane (1464 g) was added viasyringe The mixture was stirred for 30min at minus78∘C andthe bath was then removed the solution was stirred for anadditional 3 h while the temperature was increased slowlyto room temperature The reaction mixture was next pouredinto 500mL of dichloromethane (DCM) and 200mL of 1MNH4Cl solution The organic phase was separated washed

with water dried over sodium sulfate and concentratedThe residue was crystallized with methanol to remove 16-dibromohexane The resultant precipitate was purified withsilica-gel column chromatography using chloroformhexane(150 vv) and then crystallized in methanol to afford 256 gof solid yield 52

1H-NMR (300MHz CDCl3) 120575(ppm) 716 (dd 1198691= 52Hz 119869

2

= 16Hz 1H) 709 (dd 1198691= 40Hz 119869

2= 16Hz 1H) 698 (d J

= 40Hz 1H) 694 (d J = 40Hz 1H) 667 (d J = 40Hz 1H)342 (t 2H) 279 (t 2H) 186 (m 2H) 169 (m 2H) 137ndash151(m 4H)

5-Bromo-51015840-(6-bromohexyl)-221015840-bithiophene 3 A solutionof 5-(6-bromohexyl)-221015840-bithiophene 2 (92 g 28mmol) in150mLDCMwas cooled to 0∘CN-Bromosuccinimide (NBS53 g 30mmol) was added The mixture was stirred at roomtemperature overnightThen 200mL water was added to thereaction mixture The organic phase was separated washedwith water dried over sodium sulfate and concentrated Theresidue was purified with silica-gel column chromatographyusing hexane to afford 943 g of colorless oil yield 83

1H-NMR (300MHz CDCl3) 120575(ppm) 694 (d J = 40Hz 1H)691 (d J = 40Hz 1H) 683 (d J = 40Hz 1H) 667 (d J =

40Hz 1H) 341 (t 2H) 279 (t 2H) 187 (m 2H) 169 (m2H) 137ndash151 (m 4H)

5-Dodecyl-51015840-(6-bromohexyl)-221015840-quaterthiophene 6 5-Bromo-51015840-(6-bromohexyl)-221015840-bithiophene 3 (322 g7mmol) 2-(51015840-dodecyl-221015840-bithiophen-5-yl)-4455-tetram-ethyl-132-dioxaborolane 5 (284 g 7mmol) and tetrakis(triphenylphosphine) palladium (230mg 02mmol) weredissolved in 50mL of toluene under an argon atmosphereThe resultant mixture was stirred at room temperaturefor 5min before an aqueous K

2CO3solution (15mL 2M)

was added The mixture was stirred for 24 h at 90∘C undernitrogen Then the mixture was cooled down to roomtemperature and neutralized with 1M HCl solution Theorganic layer was separated and the aqueous phase wasextracted with DCM The combined organic layer wascondensed and the residue was purified with silica-gelcolumn chromatography using chloroformhexane (15 vv)to afford 301 g of yellow solid yield 65

1H-NMR (300MHz CDCl3) 120575(ppm) 704 (d J = 40Hz 2H)699 (d J = 40Hz 2H) 697 (d J = 40Hz 2H) 669 (m 2H)342 (t 2H) 276ndash283 (m 4H) 185ndash190 (m 2H) 165ndash173(m 4H) 126ndash147 (m 22H) 088 (t 3H)

Anal Calcd for C34H45BrS4 C 6170 H 685 Br 1207 S1938 Found C 6178 H 675 Br 1209 S 1935MS (MALDI-TOF)119898119911 [M]+ Calcd for C

34H45BrS4 66189 found 6621

5-Dodecyl-51015840 -(6-ethanethioatehexyl)-221015840 -quaterthiophene7 A solution of 5-dodecyl-51015840-(6-bromohexyl)-221015840-qua-terthiophene 6 (199 g 3mmol) and potassium thioacetate(068 g 6mmol) in 100mL NN-dimethylformamide wasstirred at 90∘C overnight Then the mixture was cooleddown to room temperature and 100mL water was added tothe reaction mixture The resultant precipitate was filteredand washed with methanol and then purified with silica-gelcolumn chromatography using chloroformhexane (11 vv)After that it was crystallized in THFmethanol to afford 171 gof yellow solid yield 87

1H-NMR (300MHz CDCl3) 120575(ppm) 703 (d J = 40Hz 2H)699 (d J = 40Hz 2H) 697 (d J = 40Hz 2H) 668 (m2H) 287 (t 2H) 279 (t 4H) 233 (s 3H) 166ndash170 (m 6H)126ndash142 (m 22H) 088 (t 3H)

Anal Calcd for C36H48OS5 C 6580 H 736 O 243 S 2440Found C 6577 H 742 S 2432 MS (MALDI-TOF) 119898119911[M]+ Calcd for C

36H48OS5 65709 found 65720

5-Dodecyl-51015840-(6-thiolhexyl)-221015840-quaterthiophene 4TT 5-Dodecyl-51015840-(6-ethanethioatehexyl)-221015840-quaterthiophene 7(151 g 23mmol) was dissolved in 100mL THF A solutionof potassium hydroxide (028 g 5mmol) in 5mL ethanolwas added and the mixture was stirred at room temperatureovernight Then 200mL of water was added slowly toprecipitate out the product The resultant precipitate was




13C-NMR (100MHz CDCl3) 120575(ppm) 14567 14525 1367213659 13537 13527 13453 13440 12492 12483 1240012359 12335 3388 3192 3159 3141 3019 3007 29642936 2907 2845 2805 2460 2270 1415










2






4TT

SS

SS

SS

SS

SS

SS

SS

SS

Br

Br

Br

BrBrBr

Br SS

BO

O

SS

SSS

H

NBS

BuLi

BuLi

BuLi

KOH

OB

OO

1

2

3

4

5

6

7

H3COCS

KSCOCH3

Pd(PPh3)4Na2CO3

+









SS

SSS

S SS S

SS

SSS

S

SSS

S

S

SS

SS

S

SSS

S S

SS

SS

S

S

SSS

SSS

SS

S

SS

SS

SS

S SS

S

SS

S

S

S

4TTG

(a)

5nm

20nm(b)


(i)(ii)

(iii)(iv)

00

02

04

06

08

10

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

00

02

04

06

08

10

PL in

tens

ity (a

u)

(a)

(i)(ii)

00

02

04

06

08

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

(b)






119892




40minus45

5

4

4

3

32

21

1

0 0

minus4

minus2

0

2

4

(nm

)

(nm

)

(120583m)

(120583m)

(a)

0

5

4

3

2

1

0

5

4

3

2

1minus5

minus25

0

25

5

minus505

(120583m)

(120583m)

(nm

)

(nm

)

(b)


Au Au

4TTG P3HT

SiO2

Si+n

(a)

Gate voltage (V)

(1)(2)

(3)(4)


10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

Dra

in cu

rren

t (A

)

(b)







Al

Al

Glass substrate

4TTG P3HT

SS

SS

P3HT

(a)

Write

ReadErase

(4)

(1)(2)(3)


Voltage (V)

Curr

ent (

A)

10minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

10minus3

(b)





4 Conclusion






Acknowledgments


References

































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




13C-NMR (100MHz CDCl3) 120575(ppm) 14567 14525 1367213659 13537 13527 13453 13440 12492 12483 1240012359 12335 3388 3192 3159 3141 3019 3007 29642936 2907 2845 2805 2460 2270 1415










2






4TT

SS

SS

SS

SS

SS

SS

SS

SS

Br

Br

Br

BrBrBr

Br SS

BO

O

SS

SSS

H

NBS

BuLi

BuLi

BuLi

KOH

OB

OO

1

2

3

4

5

6

7

H3COCS

KSCOCH3

Pd(PPh3)4Na2CO3

+









SS

SSS

S SS S

SS

SSS

S

SSS

S

S

SS

SS

S

SSS

S S

SS

SS

S

S

SSS

SSS

SS

S

SS

SS

SS

S SS

S

SS

S

S

S

4TTG

(a)

5nm

20nm(b)


(i)(ii)

(iii)(iv)

00

02

04

06

08

10

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

00

02

04

06

08

10

PL in

tens

ity (a

u)

(a)

(i)(ii)

00

02

04

06

08

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

(b)






119892




40minus45

5

4

4

3

32

21

1

0 0

minus4

minus2

0

2

4

(nm

)

(nm

)

(120583m)

(120583m)

(a)

0

5

4

3

2

1

0

5

4

3

2

1minus5

minus25

0

25

5

minus505

(120583m)

(120583m)

(nm

)

(nm

)

(b)


Au Au

4TTG P3HT

SiO2

Si+n

(a)

Gate voltage (V)

(1)(2)

(3)(4)


10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

Dra

in cu

rren

t (A

)

(b)







Al

Al

Glass substrate

4TTG P3HT

SS

SS

P3HT

(a)

Write

ReadErase

(4)

(1)(2)(3)


Voltage (V)

Curr

ent (

A)

10minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

10minus3

(b)





4 Conclusion






Acknowledgments


References

































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


4TT

SS

SS

SS

SS

SS

SS

SS

SS

Br

Br

Br

BrBrBr

Br SS

BO

O

SS

SSS

H

NBS

BuLi

BuLi

BuLi

KOH

OB

OO

1

2

3

4

5

6

7

H3COCS

KSCOCH3

Pd(PPh3)4Na2CO3

+









SS

SSS

S SS S

SS

SSS

S

SSS

S

S

SS

SS

S

SSS

S S

SS

SS

S

S

SSS

SSS

SS

S

SS

SS

SS

S SS

S

SS

S

S

S

4TTG

(a)

5nm

20nm(b)


(i)(ii)

(iii)(iv)

00

02

04

06

08

10

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

00

02

04

06

08

10

PL in

tens

ity (a

u)

(a)

(i)(ii)

00

02

04

06

08

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

(b)






119892




40minus45

5

4

4

3

32

21

1

0 0

minus4

minus2

0

2

4

(nm

)

(nm

)

(120583m)

(120583m)

(a)

0

5

4

3

2

1

0

5

4

3

2

1minus5

minus25

0

25

5

minus505

(120583m)

(120583m)

(nm

)

(nm

)

(b)


Au Au

4TTG P3HT

SiO2

Si+n

(a)

Gate voltage (V)

(1)(2)

(3)(4)


10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

Dra

in cu

rren

t (A

)

(b)







Al

Al

Glass substrate

4TTG P3HT

SS

SS

P3HT

(a)

Write

ReadErase

(4)

(1)(2)(3)


Voltage (V)

Curr

ent (

A)

10minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

10minus3

(b)





4 Conclusion






Acknowledgments


References

































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


SS

SSS

S SS S

SS

SSS

S

SSS

S

S

SS

SS

S

SSS

S S

SS

SS

S

S

SSS

SSS

SS

S

SS

SS

SS

S SS

S

SS

S

S

S

4TTG

(a)

5nm

20nm(b)


(i)(ii)

(iii)(iv)

00

02

04

06

08

10

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

00

02

04

06

08

10

PL in

tens

ity (a

u)

(a)

(i)(ii)

00

02

04

06

08

Abso

rban

ce (a

u)

400 500 600 700 800300Wavelength (nm)

(b)






119892




40minus45

5

4

4

3

32

21

1

0 0

minus4

minus2

0

2

4

(nm

)

(nm

)

(120583m)

(120583m)

(a)

0

5

4

3

2

1

0

5

4

3

2

1minus5

minus25

0

25

5

minus505

(120583m)

(120583m)

(nm

)

(nm

)

(b)


Au Au

4TTG P3HT

SiO2

Si+n

(a)

Gate voltage (V)

(1)(2)

(3)(4)


10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

Dra

in cu

rren

t (A

)

(b)







Al

Al

Glass substrate

4TTG P3HT

SS

SS

P3HT

(a)

Write

ReadErase

(4)

(1)(2)(3)


Voltage (V)

Curr

ent (

A)

10minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

10minus3

(b)





4 Conclusion






Acknowledgments


References

































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


40minus45

5

4

4

3

32

21

1

0 0

minus4

minus2

0

2

4

(nm

)

(nm

)

(120583m)

(120583m)

(a)

0

5

4

3

2

1

0

5

4

3

2

1minus5

minus25

0

25

5

minus505

(120583m)

(120583m)

(nm

)

(nm

)

(b)


Au Au

4TTG P3HT

SiO2

Si+n

(a)

Gate voltage (V)

(1)(2)

(3)(4)


10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

Dra

in cu

rren

t (A

)

(b)







Al

Al

Glass substrate

4TTG P3HT

SS

SS

P3HT

(a)

Write

ReadErase

(4)

(1)(2)(3)


Voltage (V)

Curr

ent (

A)

10minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

10minus3

(b)





4 Conclusion






Acknowledgments


References

































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Al

Al

Glass substrate

4TTG P3HT

SS

SS

P3HT

(a)

Write

ReadErase

(4)

(1)(2)(3)


Voltage (V)

Curr

ent (

A)

10minus11

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

10minus3

(b)





4 Conclusion






Acknowledgments


References

































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





Acknowledgments


References

































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

research article synthesis of gold nanoparticles capped...

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