Efficiency enhancement of the thin-silicon photovoltaics using indium-tin-oxide nanowhiskers

Abstract

Thin wafer-based solar cells have the potential to significantly decrease the cost of photovoltaics. Light trapping is particularly critical in such thin-wafer crystalline silicon solar cells in order to increase light absorption and hence cell efficiency. In this article we investigate the indium-tin-oxide nanowhisker on textured silicon surface for enhancing the near-infrared absorbance of silicon photovoltaics. The nanowhiskers facilitate optical transmission in the near-infrared by functioning as impedance matching layers with effective refractive indices gradually varying from 1 to 1.3. Materials with such unique refractive index characteristics are not readily available in nature. As a result, the solar cell with combined textures achieves quantum efficiencies enhancement for a broad wavelength range of 900 to 1100 nm, which is crucial to the development of advanced thin-substrate silicon solar cells.