poster_cers 2016_direct graphene-si solar cells_xin yu
TRANSCRIPT
Transfer-Free Development of Graphene-on-Silicon Heterojunction Solar CellsXin Yu, Craig Shaffer, Sanjay Behura, and Vikas Berry
University of Illinois at Chicago, Illinois 60607, United States
Photovoltaic and Spectral Responses
Acknowledgements: University of Illinois at Chicago
Solar device fabrications were made via standard photolithography and metallization processes
Graphene Characterizations
600 700 800 9001.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Qu
an
tum
Eff
icie
nc
y (
%)
Wavelength (nm)
Motivations
Results and Discussions
Experimental Approach
Conclusion and Future Directions References
• Energy from sunlight strikes the earth in 1 h (4.3x1020 J) is morethan all of the energy currently consumed on the planet in 1 year(4.1x1020 J). Yet, only <0.25% of total electricity is generated fromsolar (2013).
• Solar energy in wavelength from 600 to 1400 nm doesn’t getabsorbed fully by the standard Si P-N junction solar cells.
• Graphene/Si solar cells hold promise due to graphene’sbroadband absorption, and high carrier mobility.
Chemical Vapor Deposition setup
• Scanning Raman spectroscopywith 532 nm laser excitationwas employed to evaluate thedirectly grown graphene:thickness, defects, continuity,and uniformity.
• From the Raman spectrum andmapping, it is confirmed thatthe few-layer graphene iscontinuously grown on n-Sisurfaces.
• Field Emission ScanningElectron Microscope (FESEM)was also used to characterizethe graphene surface with andwithout Ag nanoparticles.
D
• Transfer-free graphene/Si solar cells developed via CVD.
• PCE of 1.3% is achieved with Ag nanoparticles plasmonics.
• EQE measurements also support the expected device performance.
• H. A. Atwater and A. Polman, “Plasmonics for improved photovoltaic
devices,” Nature Materials, 9: 205-214, 2010.
• A. K. Geim and K. S. Novoselov, “The rise of graphene,” Nature Materials,
6: 183-191, 2007.
• S. Behura et al., “Junction characteristics of chemically-derived graphene-p
Si heterojunction solar cell,” Carbon, 67: 766-774, 2014.Graphene/SiNW Heterojunction Solar Cells
Parameter w/o Ag NPs with Ag NPs
Area (cm2) 0.05 0.05
Jsc (mA/cm2) 14.77425 32.45456
Voc (V) 0.219231 0.182353
Pin 0.005 0.005
Fill Factor 23.39% 21.89%
Efficiency 0.76% 1.30%
Graphene with NPs
Graphene w/o NPs
Source: Key World Energy Statistics 2015 H. A. Atwater, A. Polman, Nat. Mater. (2010)
Schematic of graphene/n-Si solar cell J-V characteristics
Cell performances EQE characteristics