Enhancement of optical absorption by Nano particles
- Paper number
IAC-12,C2,4,10,x14527
- Author
Dr. Yongan Tang, United States
- Coauthor
Prof. Branislav Vlahovic, North Carolina Central University, United States
- Year
2012
- Abstract
One major challenge for photovolatics solar cell is to improve its light-to-electrical efficiency while reducing its cost and weight. Scientists are investigating many methods to improve the solar cells light-to electrical efficiency. Thin film solar cells satisfy the demand of the high efficiency, low cost, and low weight. Since most of the solar cells are based on the crystalline silicon wafer with the thickness between 200 and 300μm, and around 40% of the cost is the silicon wafer. The hydrogenated alloy of amorphous silicon (a-Si:H) has high optical absorption than other materials, a-Si:H thin film solar cells are able to improve the absorption efficiency, since the minority carrier diffusion length is less than or around 300nm for amorphous silicon. However, a limitation in all thin film solar cell technologies is that absorbance of red spectrum is too small, because of silicon indirect bandgap. To overcome these light-trapping problems and to increase light absorption, new method based on excitation of surface plasmons via scattering from noble metal nanostructures was proposed. We study the optical absorption efficiency of the a-si:H thin film with nano-metallic particles, and investigate the size and shape of these nano-particles. Our research shows that for a 100nm thick a-Si:H thin film, deposit an array of nano-metallic cubes or cylinders will increase the optical absorption in the red light (e.g. 650nm) dramatically. These nano-particle thin film solar cells can also be used for spacecraft.
- Abstract document
- Manuscript document
IAC-12,C2,4,10,x14527.pdf (🔒 authorized access only).
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