controlled synthesis of single-crystal snse nanoplates · 2014-12-08 · controlled synthesis of...

Nano Res

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Controlled synthesis of single-crystal SnSe nanoplates


Nano Res., Just Accepted Manuscript • DOI: 10.1007/s12274-014-0676-8

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Nano Research

DOI 10.1007/s12274-014-0676-8


Shuli Zhao, Huan Wang, Yu Zhou, Lei Liao, Ying Jiang,

Xiao Yang, Guanchu Chen, Min Lin, Yong Wang, Hailin

Peng*, and Zhongfan Liu*

Peking University, China

Single-crystal SnSe nanoplates have been synthesized on the mica

substrates by vapor deposition method. SnSe nanoplates show a p-type

conductivity and a high photoresponsivity.



Received: day month year

Revised: day month year

Accepted: day month year

(automatically inserted by

the publisher)

© Tsinghua University Press

and Springer-Verlag Berlin

Heidelberg 2014

KEYWORDS

SnSe,

IV-VI chalcogenide,

Nanoplate,

Two-dimensional layered

crystals,

Optoelectronics

ABSTRACT

Two-dimensional layered IV-VI chalcogenides are attracting great interest for

applications in next-generation optoelectronic, photovoltaic, and thermoelectric

devices. However, great challenges on the controllable synthesis of high-quality

IV-VI chalcogenides nanostructures still hinder their in-depth studies and

practical applications to date. Here we report, for the first time, a feasible

synthesis of single-crystal IV-VI SnSe nanoplates in a controlled manner on the

mica substrates by vapor transport deposition. The as-grown SnSe nanoplates

are of approximately square shapes with controllable side lengths varying from

1 to 6 microns. Electrical transport and optoelectronic measurements show that

as-obtained SnSe nanoplates display a p-type conductivity and a high

photoresponsivity.

1 Instruction

Two-dimensional (2D) layered materials have

garnered immense attentions in materials science in

recent years because of their novel properties and

various applications [1-7]. Graphene is the most

widely studied 2D material due to its prominent

electrical properties such as high carrier mobility

and the fractional quantum Hall effect [2, 8]. Other

2D layered materials such as hexagonal boron

nitride (h-BN) [3, 9], V-VI topological insulators (TIs)

[10-12] and transition metal dichalcogenides (TMDs)

[4] have also received considerable attentions,

owing to their fascinating electronic band structures

and remarkably layer-dependent properties. Tin

selenide (SnSe), a representative of layered IV-VI

chalcogenides, is an attractive binary p-type

semiconductor material with a wide range of

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2 Nano Res.

potential applications, such as memory switching

devices [13], infrared optoelectronic devices [14-16],

and anode materials to improve lithium-ion

diffusivity [17]. Bulk SnSe has an indirect band gap

of ~0.90 eV and a direct band gap of ~1.30 eV,

offering great potentials in the fields of

photovoltaics and optoelectronics [18-21]. Most

recently, ultralow thermal conductivity and high

thermoelectric figure of merit have been found in

SnSe bulk crystals [22], which have also extended

their prospects with regard to the usage in the

thermoelectric energy conversion.

Layered SnSe has an orthorhombic crystal

structure in space group Pnma (62), which can be

regarded as a severely distorted NaCl structure,

with atoms arranged in two adjacent double layers

of tin and selenium, forming a planar bilayer (BL)

structures and held together by weak van der Waals

interactions (inset of Figure 1a) [23]. In comparison

with their bulk form, 2D SnSe nanostructures are

expected to have a tunable band gap [24, 25], high

photosensitivity and quick photosensitivity [21, 25,

26], owing to the large specific surface area and the

quantum confinement effects on their electronic and

optical properties. Furthermore, 2D material

structures are more compatible with modern

micro/nano-fabrication techniques and can be easily

fabricated into complex structures for various

electronic and optoelectronic applications [27]. Due

to its layered structure and anisotropic bonding

nature, the synthesis of 2D SnSe structures would

be possible. However, up to now, major works

related to SnSe nanostructures have been focused

on the solution-phase synthesis of colloidal

nanocrystals, nanowires, and submicron nanosheets

for their applications in photovoltaic devices [19-21,

28]. Hence, exploring a feasible and controllable

method to synthesize 2D single-crystal SnSe

nanostructures with large grain sizes and high

quality is quite imperative.

Here we report, for the first time, a facile

vapor-phase synthesis of single-crystal SnSe

nanoplates (NPs) on the transparent flexible mica

substrates. The as-grown SnSe NPs are of

approximately square shapes with controllable

lateral dimensions varying from 1 to 6 microns.

Electrical transport and optoelectronic

measurements show that as-obtained SnSe NPs

Figure 1 Morphology of synthetic SnSe NPs. (a) Schematic diagram of vapor deposition of SnSe NPs on the mica substrates. Inset

shows layered orthorhombic SnSe with each bilayer (BL) formed of Se and Sn atoms. The thickness of 1 BL is about 5.75 Å. The

blue and yellow spheres represent tin and selenium atoms, respectively. (b) 2D SnSe NPs grown on a transparent flexible mica flake.

Inset shows a photograph of 2D SnSe NPs grown on the mica substrates. (c) Optical micrograph of SnSe NPs on the mica substrates.

(d) SEM image of SnSe NPs on the mica substrates. (e) AFM image of a single SnSe NP with a Z-scale of 50 nm.

display a p-type conductivity and a high

photoresponsivity.

www.theNanoResearch.com∣www.Springer.com/journal/12274 | Nano Research

3 Nano Res.

2 Experimental

A schematic representation of 2D SnSe NPs growth

is illustrated in Figure 1a (See the Methods for

detailed synthetic procedure). Generally, a freshly

cleaved mica sheet, which is atomically flat and free

from surface dangling bonds [29-31], served as the

substrates for the vapor evaporation and deposition

growth of 2D SnSe in a low-pressure vapor

deposition system (Figure 1b). Bulk SnSe powder,

used as the single precursor, firstly evaporated

congruently to major vapor species SnSe and Sn2Se2

in the high temperature zone [32]. Then the cluster

vapor was transported by argon carrier gas to the

mica substrates at downstream cold zone. Finally

the vapor deposited and grew into NPs on the mica

surface.

3 Results and discussion

The morphology of the as-synthesized SnSe NPs was

characterized by optical microscopy (OM), scanning

electron microscopy (SEM) and atomic force

microscopy (AFM). The typical optical micrograph

and SEM image (Figure 1c, d) show that the SnSe

NPs with a square shape randomly distribute on the

mica substrates, rather than controlled-orientation

NPs alignment [29]. SnSe NPs have approximately

square shapes with lateral dimensions about 5~6

microns. Individual NP shows uniform color contrast,

implying an identical thickness across the whole

plane of the NP. The thickness of the SnSe NPs was

further determined by AFM. Figure 1e displays an

AFM image and the corresponding height profile of

a SnSe NP, revealing a very flat top surface with a

height of about 15.8 nm. Extensive height

measurements indicate that the thickness of SnSe

NPs mainly varies between 6 nm and 40 nm

depending on the growth conditions.

In order to obtain the detailed crystal structure

and crystal quality of the synthesized products,

SnSe NPs were characterized by transmission

electron microscopy (TEM), high-angle annular

dark-field scanning transmission microscopy

(HAADF-STEM) and the selected-area electron

diffraction (SAED). Figure 2a shows a typical

low-magnification TEM image of 2D SnSe NPs

transferred onto a holey carbon film. The SnSe NPs

are relatively stable against the electron beam

irradiation in a TEM. The high-resolution TEM

(HR-TEM) image of the rectangular area in Figure

2a, shows clear orthogonal lattice fringes, with both

lattice spacing of about 0.30 nm. The intersection

Figure 2 TEM characterization of SnSe NPs. (a) Low

magnification TEM image of SnSe NPs. (b) High-resolution

TEM image of the SnSe NP of the rectangular area of (a). (c)

The SAED pattern of the single SnSe NP in (a). (d) Low

magnification TEM image of a single SnSe NP which was

folded during the transfer process. (e) A magnified image of the

rectangular area of the inset which is the corresponding

HR-TEM image of the rectangular area of (d). (f)

High-resolution and low-magnification (inset) cross-sectional

z-contrast images of the SnSe NP on the mica substrates.

angle of the lattice fringes is approximated 92o

(Figure 2b), which is in good agreement with the

planes of (011) of the orthorhombic SnSe crystal


4 Nano Res.

structure [23, 25]. The SAED data (Figure 2c), taken

from the individual SnSe NP, exhibits a clear

orthogonally symmetric spot pattern, indicative of

the single-crystal nature of the sample. Moreover, it

can be concluded from the SAED pattern that the

SnSe NP has the surface normal oriented along the

[100] direction [25, 33-35], which matches well the

single [100] orientation obtained with the aid of

XRD in Figure 3e. Figure 2d shows a TEM image of

the SnSe NP with a folded edge, formed during the

sample preparation stage for the TEM

characterization. It reveals that the thin SnSe NPs

have a good flexibility and can be easily bent to

∼180o without any fracture. The corresponding

HR-TEM image of the framed folded edge area is

shown in Figure 2e. The magnified HR-TEM lattice

fringes illustrate a layer spacing of 0.58 nm along

the [100] stacking orientation, which is in good

agreement with the theoretical results [18]. The

thickness of the SnSe NP is measured as ~6.3 nm

from the folded edge, corresponding to ~11 BLs.

High-resolution cross-sectional z-contrast image of

the SnSe NPs on the mica substrates was acquired

by the HAADF detector under the STEM mode,

which is another strong evidence to demonstrate

the layered single-crystal nature of SnSe NPs.

Besides, it also displays a thickness of

approximated 0.58 nm of two atomic layers (1 BL of

SnSe).

The spectroscopic characterizations were also

performed to evaluate the structure and quality of

SnSe NPs. As illustrated in Figure 3b and 3c, EDX

elements mapping images indicate that Sn and Se

elements are uniformly distributed, confirming the

uniform chemical distribution along the entire NP.

The corresponding EDX spectrum shows a Sn/Se

atomic ratio of 1:1 (Figure 3d). Moreover, X-ray

photoelectron spectroscopy (XPS) was employed to

corroborate the chemical composition with a

near-stoichiometric of Sn: Se = 49%: 51% (Figure S1).

The X-ray diffraction (XRD) spectrum of

as-prepared SnSe NPs can be indexed to be

orthorhombic SnSe structure (JCPDS No. 48-1224, a:

11.498 Å , b: 4.153 Å , c: 4.440 Å ) (Figure 3e). It is

worth-noting that the predominant peaks are (400)

and (800), which reveal highly orientation of NPs

grown on the mica substrates, consistent with the

above-mentioned SAED data.

Raman spectroscopy was also performed to

provide more information about the quality of

as-prepared SnSe NPs. Ag and B3g are two rigid shear

modes of a layer with respect to its neighbors in the b

and c directions, respectively, which indicate planar

vibration modes of SnSe [36]. As illustrated in Figure

3f, four characteristic peaks are clearly observed at

70.0, 105.5, 127.7 and 148.2 cm-1, respectively. The

raman peak of the highest intensity at 105.5 cm-1

corresponds to the B3g phonon mode, whilst the other

three peaks belong to Ag phonon modes [36]. The

Figure 3 Spectroscopic characterizations of SnSe NPs. (a)

High-angle annular dark-field imaging (HAADF) of a SnSe NP.

(b, c) Sn and Se element maps of the corresponding SnSe NP,

respectively. (d) The corresponding EDX spectra of the SnSe

NP. The Cu signal comes from Cu grid. (e) XRD spectra of the

SnSe NPs and the powder source with the corresponding

simulated spectrum of SnSe crystals. (f) The Raman spectrum

of a SnSe NP. Inset shows the optical image of the SnSe NP. (g)

The corresponding Raman map of B3g phonon mode intensity

of the SnSe NP of (f).

corresponding Raman mapping of B3g characteristic

peak of the SnSe NP is shown in Figure 3g. A

uniform color contrast and high intensity reveal


5 Nano Res.

that the SnSe NP presents a high crystallinity.

We have achieved a controllable synthesis of

square shaped SnSe NPs with different side lengths

varying from 1 μm to 6 μm, as shown in Figure 4a-f.

As far as we know, temperature and pressure are

the main control factors in a vapor deposition

system. The temperature is crucial to the

evaporation quantity of SnSe powder source, while

the pressure mainly affects the nucleation and

growth. When a lower evaporation temperature of

500 oC, deposition temperature of 340~390 oC, and

pressure of 70 torr were employed, square shaped

SnSe NPs with side length of 1μm were obtained.

By increasing the evaporation temperature of SnSe

source but keeping the deposition temperature and

the pressure identical, the side length of SnSe NPs

would elongate and hence SnSe NPs with different

side lengths of 1~6 μm were obtained. Statistic

histograms of square shaped SnSe NPs with

different side lengths are illustrated in Figure 4g,

indicating that the samples (Figure S2) possess good

side lengths distributions. In addition, SnSe NPs

with smaller size and rounded corners would grow

when the evaporation temperature was lower than

500 oC (Figure S3). The extremely precise control of

the NP size and thickness requires a better

understanding of the crystal growth mechanism in

the current system, where further study is

underway.

To study the electrical properties of

as-synthesized SnSe NPs, electrical transport

measurements of individual SnSe NPs at room

temperature were carried out. A schematic

depiction of the device is shown in Figure 5a. To

fabricate the devices with four-electrode

configuration, SnSe NPs were transferred onto

silicon substrates covered with 300-nm-thick SiO2

dielectric from the mica growth substrates, followed

by a standard electron beam lithography (EBL) and

Figure 4 Optical micrographs and statistics of SnSe NPs with different side lengths. (a-f) Optical micrographs of SnSe NPs on the

mica substrates with the side lengths varying from 1μm to 6 μm. (g) Statistics of SnSe NPs with different side lengths.


6 Nano Res.

Figure 5 Electrical and photoresponse properties of SnSe NPs. (a) Three-dimensional schematic view of the SnSe NPs transistor. (b)

Two-probe and four-probe I-Vds characteristics for the device. Inset: OM image of the device, scale bar: 5 μm. (c) Transport

characteristic curve of the device at Vds= 0.1 V. (d) Output characteristic curves of the device at different Vg values (from -40 V to 40

V using step of 10 V). (e) The time trace of photocurrent response for the device with an incident light switched on and off at a bias

voltage of 0.1 V.

thermal deposition of metal electrodes (8 nm Cr and

70 nm Au). To extract the intrinsic resistance of the

NP device from the contact resistance, four-probe

measurements were performed. In Figure 5b, the

source-drain current (I) versus voltage (Vds)

characteristics at zero gate voltage (Vg) of the device

(inset of Figure 5b, more information in Figure S4)

from four-probe and two-probe measurements are

linear but match not well, revealing a Schottky

contact by Cr/Au contact. The intrinsic resistance of

the NP is ~0.34 MΩ and the corresponding

conductance is 0.28 S cm-1.

The transfer measurement of the device with

applied bias voltage (Vds) of 0.1 V is shown in

Figure 5c. The conductance decreases upon a

positive Vg scan, displaying a p-type

semiconducting characteristic, mainly due to

residual doping from intrinsic defects such as Sn

vacancies [18, 24]. Figure 5d illustrates I-Vds curves

for different Vg values (from -40 V to +40 V using

step of 10 V). From the data presented in Figure 5c,

we can evaluate the field-effect mobility of ~1.5 cm2

V-1 s-1, using the equation μ= [dI/dVg] x [L/

(WCgVds)], where L = 1 μm, W = 5.2 μm and Cg =

11.5 nF cm-2 (Cg = εrε0/d, εr = 3.9, d = 300 nm) are the

channel length, width and the gate capacitance per

unit area. It is noteworthy that the value is

comparable with the mobility of the thin layered

MoS2 without high κ dielectric [37]. However, the

mobility is much smaller than bulk SnSe material

[16, 38]. This could be ascribed to the exacerbation

of phonon scattering because of severely doping

effects from intrinsic Sn vacancies [16, 18, 38] and a

Schottky contact. What we would like to highlight

here is that this is the first field-effect transistor

(FET) based on single-crystal 2D SnSe

nanostructures.

The optoelectronic properties of the SnSe NPs

were also investigated. As shown in Figure 5e, upon

white-light illumination, the device shows an

obvious current change (~0.06 μA increase) at a bias

voltage of 0.1 V. Given the incident light intensity of

3.5 mW cm-2 and the active area of the device of ~5.2

μm2 the photoresponsivity of SnSe NPs is calculated

to be ~330 A W-1.


7 Nano Res.

4 Conclusion

Single-crystal orthorhombic SnSe nanoplates with

different sizes have been successfully synthesized

on the mica substrates by a vapor transport

deposition method. The structure and chemical

composition of as-prepared SnSe NPs were

confirmed by SEM, AFM, Raman, XRD, TEM and

EDX. The SnSe NPs show a p-type conducting

property and high photoresponsivity. As a thin

layered semiconductor material with a suitable

band gap, SnSe NPs offer great potentials in the

fields of optoelectronics and energy harvesting.

Meanwhile, since bulk SnSe crystal has ultralow

thermal conductivity and high thermoelectric figure

of merit, the SnSe nanostructures have huge

potentials for further applications in energy

conversion.

5 Methods

5.1 Synthesis of single-crystal SnSe NPs

SnSe NPs were grown inside of a horizontal tube

furnace (Lindburg/Blue M) with a 1 inch diameter

quartz tube. SnSe powder (99.999%, Alfa Aesar) was

located at the center of the furnace, while the

freshly cleaved mica substrates ([KMg3(AlSi3O10)F2],

Tiancheng Fluorphlogopite Mica Company Ltd,

China) were placed downstream at certain locations

to keep deposition temperature of 340~390 oC. The

quartz tube was pumped and refilled of ultra-pure

argon gas more than three times to reduce oxygen

contamination. The furnace was heated to 500~550 oC in 15 min, and kept for 1~10 min with growth

pressure of 70~200 Torr, argon flow rate of 60~100

sccm, then cooled down to room temperature

naturally. When the growth process was complete,

SnSe NPs were obtained on the surface of the mica

substrates.

5.2 Characterization of SnSe NPs

Optical micrograph images were acquired by an

Olympus DX51 optical microscopy. SEM images

were obtained by a Hitachi S4800 field-emission

scanning electron microscopy. AFM was performed

on a Vecco IIIa Nanoscope using tapping mode.

TEM images and EDX spectrum were collected

using a FEI F30 transmission electron microscopy

and its equipped energy dispersive X-ray

spectroscopy, while high-resolution z-contrast

image was acquired by the HAADF detector under

the scanning transmission electron microscopy

(Tecnai G2 F20 S-TWIN, FEI) mode. Raman spectra

were obtained on a Horiba HR800 Raman system

using low power of ~0.225 mW at 514 nm laser

excitation. XRD spectrum was carried out using a

Regaku D/Max-2500 diffractometer equipped with a

Cu Kα1 radiation at the work voltage of 40 V.

5.3 Fabrication of devices

Firstly, SnSe NPs were transferred onto the p-type

silicon substrate covered with 300-nm-thick SiO2

dielectric from the mica substrates using a

PMMA-mediated transfer technique. Then, the

contact electrodes were fabricated by a standard

electron beam lithography and thermal deposition

of metal (8 nm Cr and 70 nm Au). Electrical

transport measurements were carried out using a

Keithley 4200-SCS semiconductor system at room

temperature.

Acknowledgements

We thank Qianfan Zhang for helpful discussion.

This work was financially supported by the

National Natural Science Foundation of China (Nos.

21173004, 21222303, 51121091, 51290272, and

51222202), the National Basic Research Program of

China (Nos. 2011CB921904, 2013CB932603,

2014CB932500, and 2012CB933404), the

Fundamental Research Funds for the Central

Universities (No. 2012QNA4005), and National

Program for Support of Top-Notch Young

Professionals.

References

[1] Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.;

Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A.


8 Nano Res.

A. Electric field effect in atomically thin carbon films.

Science 2004, 306, 666-669.

[2] Geim, A. K.; Novoselov, K. S. The rise of graphene.

Nat. Mater. 2007, 6, 183-191.

[3] Kubota, Y.; Watanabe, K.; Tsuda, O.; Taniguchi, T.

Deep ultraviolet light-emitting hexagonal boron nitride

synthesized at atmospheric pressure. Science 2007, 317,

932-934.

[4] Mak, K. F.; Lee, C.; Hone, J.; Shan, J.; Heinz, T. F.

Atomically Thin MoS2: A New Direct-Gap

Semiconductor. Phys. Rev. Lett. 2010, 105, 106805.

[5] Matte, H. S. S. R.; Gomathi, A.; Manna, A. K.; Late, D.

J.; Datta, R.; Pati, S. K.; Rao, C. N. R. MoS2 and WS2

Analogues of Graphene. Angew. Chem. Int. Edit. 2010,

49, 4059-4062.

[6] Radisavljevic, B.; Radenovic, A.; Brivio, J.; Giacometti,

V.; Kis, A. Single-layer MoS2 transistors. Nat.

Nanotech 2011, 6, 147-150.

[7] Huang, X.; Zeng, Z. Y.; Zhang, H. Metal

dichalcogenide nanosheets: preparation, properties and

applications. Chem. Soc. Rev. 2013, 42, 1934-1946.

[8] Bolotin, K. I.; Ghahari, F.; Shulman, M. D.; Stormer, H.

L.; Kim, P. Observation of the fractional quantum Hall

effect in graphene. Nature 2009, 462, 196-199.

[9] Dean, C. R.; Young, A. F.; Meric, I.; Lee, C.; Wang, L.;

Sorgenfrei, S.; Watanabe, K.; Taniguchi, T.; Kim, P.;

Shepard, K. L.; Hone, J. Boron nitride substrates for

high-quality graphene electronics. Nat. Nanotech 2010, 5,

722-726.

[10] Zhang, H. J.; Liu, C. X.; Qi, X. L.; Dai, X.; Fang, Z.;

Zhang, S. C. Topological insulators in Bi2Se3, Bi2Te3 and

Sb2Te3 with a single Dirac cone on the surface. Nat. Phys.

2009, 5, 438-442.

[11] Kong, D. S.; Randel, J. C.; Peng, H. L.; Cha, J. J.;

Meister, S.; Lai, K. J.; Chen, Y. L.; Shen, Z. X.;

Manoharan, H. C.; Cui, Y. Topological Insulator

Nanowires and Nanoribbons. Nano Lett. 2010, 10,

329-333.

[12] Peng, H. L.; Lai, K. J.; Kong, D. S.; Meister, S.; Chen, Y.

L.; Qi, X. L.; Zhang, S. C.; Shen, Z. X.; Cui, Y.

Aharonov-Bohm interference in topological insulator

nanoribbons. Nat. Mater. 2010, 9, 225-229.

[13] Chun, D.; Walser, R. M.; Bene, R. W.; Courtney, T. H.

Polarity-Dependent Memory Switching in Devices with

SnSe and SnSe2 Crystals. Appl. Phys. Lett. 1974, 24,

479-481.

[14] Agarwal, A.; Vashi, M. N.; Lakshminarayana, D.;

Batra, N. M. Electrical resistivity anisotropy in layered

p-SnSe single crystals. J. Mater. Sci-Mater. El. 2000, 11,

67-71.

[15] Boscher, N. D.; Carmalt, C. J.; Palgrave, R. G.; Parkin,

I. P. Atmospheric pressure chemical vapor deposition of

SnSe and SnSe2 thin films on glass. Thin Solid Films

2008, 516, 4750-4757.

[16] Sumesh, C. K.; Patel, M.; Patel, K. D.; Solanki, G. K.;

Pathak, V. M.; Srivastav, R. Low temperature

electrical transport properties in p-SnSe single crystals.

Eur. Phys. J-Appl.Phys. 2011, 53, 10302.

[17] Xue, M. Z.; Yao, J.; Cheng, S. C.; Fu, Z. W. Lithium

electrochemistry of a novel SnSe thin-film anode. J.

Electrochem. Soc. 2006, 153, A270-A274.

[18] Lefebvre, I.; Szymanski, M. A.; Olivier-Fourcade, J.;

Jumas, J. C. Electronic structure of tin

monochalcogenides from SnO to SnTe. Phys. Rev. B

1998, 58, 1896-1906.

[19] Baumgardner, W. J.; Choi, J. J.; Lim, Y. F.; Hanrath, T.

SnSe Nanocrystals: Synthesis, Structure, Optical

Properties, and Surface Chemistry. J. Am. Chem. Soc.

2010, 132, 9519-9521.

[20] Franzman, M. A.; Schlenker, C. W.; Thompson, M. E.;

Brutchey, R. L. Solution-Phase Synthesis of SnSe

Nanocrystals for Use in Solar Cells. J. Am. Chem. Soc.

2010, 132, 4060-4062.

[21] Liu, S.; Guo, X. Y.; Li, M. R.; Zhang, W. H.; Liu, X. Y.;

Li, C. Solution-Phase Synthesis and Characterization of

Single-Crystalline SnSe Nanowires. Angew. Chem. Int.

Edit. 2011, 50, 12050-12053.

[22] Zhao, L. D.; Lo, S. H.; Zhang, Y. S.; Sun, H.; Tan, G. J.;

Uher, C.; Wolverton, C.; Dravid, V. P.; Kanatzidis, M.

G. Ultralow thermal conductivity and high

thermoelectric figure of merit in SnSe crystals. Nature

2014, 508, 373-377.

[23] Car, R.; Ciucci, G.; Quartapelle, L. Electronic

Band-Structure of SnSe. Phys. Status. Solidi. B. 1978,

86, 471-478.

[24] Li, L.; Chen, Z.; Hu, Y.; Wang, X. W.; Zhang, T.; Chen,

W.; Wang, Q. B. Single-Layer Single-Crystalline SnSe


9 Nano Res.

Nanosheets. J. Am. Chem. Soc. 2013, 135, 1213-1216.

[25] Vaughn, D. D.; In, S. I.; Schaak, R. E. A

Precursor-Limited Nanoparticle Coalescence Pathway

for Tuning the Thickness of Laterally-Uniform Colloidal

Nanosheets: The Case of SnSe. ACS nano 2011, 5,

8852-8860.

[26] Tritsaris, G. A.; Malone, B. D.; Kaxiras, E.

Optoelectronic properties of single-layer, double-layer,

and bulk tin sulfide: A theoretical study. J. Appl. Phys.

2013, 113, 233507.

[27] Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J.

N.; Strano, M. S. Electronics and optoelectronics of

two-dimensional transition metal dichalcogenides. Nat.

Nanotech 2012, 7, 699-712.

[28] Antunez, P. D.; Buckley, J. J.; Brutchey, R. L. Tin and

germanium monochalcogenide IV-VI semiconductor

nanocrystals for use in solar cells. Nanoscale 2011, 3,

2399-2411.

[29] Li, H.; Cao, J.; Zheng, W. S.; Chen, Y. L.; Wu, D.; Dang,

W. H.; Wang, K.; Peng, H. L.; Liu, Z. F. Controlled

Synthesis of Topological Insulator Nanoplate Arrays on

Mica. J. Am. Chem. Soc. 2012, 134, 6132-6135.

[30] Dang, W. H.; Peng, H. L.; Li, H.; Wang, P.; Liu, Z. F.

Epitaxial Heterostructures of Ultrathin Topological

Insulator Nanoplate and Graphene. Nano Lett. 2010, 10,

2870-2876.

[31] Peng, H. L.; Dang, W. H.; Cao, J.; Chen, Y. L.; Wu, W.;

Zheng, W. S.; Li, H.; Shen, Z. X.; Liu, Z. F.

Topological insulator nanostructures for near-infrared

transparent flexible electrodes. Nat. Chem. 2012, 4,

281-286.

[32] Colin, R.; J. Drowart, J. Thermodynamic study of tin

selenide and tin telluride using a mass spectrometer.

Trans. Faraday Soc. 1964, 60, 673-683.

[33] Vaughn, D. D.; Patel, R. J.; Hickner, M. A.; Schaak, R.

E. Single-Crystal Colloidal Nanosheets of GeS and GeSe.

J. Am. Chem. Soc. 2010, 132, 15170-15172.

[34] Yoon, S. M.; Song, H. J.; Choi, H. C. p-Type

Semiconducting GeSe Combs by a

Vaporization-Condensation-Recrystallization (VCR)

Process. Adv. Mater. 2010, 22, 2164-2167.

[35] Xue, D. J.; Tan, J. H.; Hu, J. S.; Hu, W. P.; Guo, Y. G.;

Wan, L. J. Anisotropic Photoresponse Properties of

Single Micrometer-Sized GeSe Nanosheet. Adv. Mater.

2012, 24, 4528-4533.

[36] H.R.Chandrasekhar, R. G. H., U.Zwick, and M.Cardona

Infrared and Raman spectra ofthe IV-VI compounds SnS

and SnSe. Phys. Rev. B 1977, 15, 2177-2183.

[37] Ayari, A.; Cobas, E.; Ogundadegbe, O.; Fuhrer, M. S.

Realization and electrical characterization of ultrathin

crystals of layered transition-metal dichalcogenides. J.

Appl. Phys. 2007, 101, 014507.

[38] Maier, H.; Daniel, D. R. Snse Single-Crystals -

Sublimation Growth, Deviation from Stoichiometry and

Electrical-Properties. J. Electron. Mater. 1977, 6,

693-704.


Nano Res.

Electronic Supplementary Material


Shuli Zhao1, 2, Huan Wang1, Yu Zhou1, 2, Lei Liao1, Ying Jiang3, Xiao Yang1, Guanchu Chen1, Min Lin1,

Yong Wang3, Hailin Peng1, 2 () and Zhongfan Liu1, 2 ()

Figure S1 XPS spectra of SnSe nanoplates (NPs). (a) Simulated (red, green and blue) and experimental (black) high-resolution Se 3d

spectra. (b) Simulated (red) and experimental (black) high-resolution Sn 3d spectra.

Address correspondence to [email protected]; [email protected]

mailto:[email protected]


Nano Res.

Figure S2 Optical micrographs of SnSe NPs with different side lengths for statistics. (a-f) Optical micrographs of SnSe NPs on the

mica substrates with the side lengths varying from 1μm to 6 μm.

Figure S3 Optical micrograph and SEM image of SnSe NPs with lateral dimension size less than 1 μm and rounded corners. (a)

Optical micrograph. (b) SEM image.

Figure S4 AFM image of a SnSe NP device with a Z-scale of 300 nm.

controlled synthesis of single-crystal snse nanoplates · 2014-12-08 · controlled synthesis of...

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