Optimized periodic surface texture for heterojunction a-Si/c-Si solar cells

• Main Authors: Yen-Chih Pan, 潘彥志
• Other Authors: Chih-Ming Wang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/40522688646943529711

碩士 === 國立東華大學 === 光電工程學系 === 99 === Because of the finite deposits of coal, oil and gas in earth, people have to search for a renewable energy. For the reason that solar energy will never run out, solar cell, which can turn light into electricity, is most considerable. The conversion efficiency of solar cell is still low due to the band gap of absorption layer, carrier recombination and surface reflection. As the thickness of a-Si is enough, the incident light waves can be sandwiched in a-Si layer by air and c-Si layer to result in planar waveguide. Light trapping from surface texturing and planar waveguide can prolong the light path in solar cell and enhance the absorption of thin film solar cell. Textured surface also can reduce the reflection of interface for the usage of anti-reflection coating to enhance the efficiency. In this thesis, we changed the shape of grating to find the best short circuit current density, then plotted the contour map as the function of grating parameters such as duty cycle, period and etching depth to find the optimized grating structure of better short circuit density for HIT( heterojunction with intrinsic thin layer) solar cell. H field distribution had also be taken into account for further study. Considering the absorption of ITO and active layer individually is necessary for the absorption at long wavelength of ITO is useless to generate hole-electron pair. At last we neglected the absorption from ITO and ensure the ability of light absorption of active layer after periodic surface texturing.