硅太阳电池表面多孔硅的制备与作用

摘要

A layer of porous silicon was formed on the surface of the pyramids on the silicon using the electrochemical method.The effect of the porous silicon on the reflectivity of surface as well as the photovoltaic conversion quantum efficiency and the effect of oxidation on the photovoltaic conversion quantum efficiency for different wavelengths were studied.It was observed that the density of hydrofluoric acid (HF) did not make a difference on the reflectivity of the surface,and the electrochemical etching time can determine the minimun-reflection wavelength.The average reflectivity of the structure can be 2％.Because of the porous silicon,the photovoltaic conversion quantum efficiency is decreased for the wavelength between 300 ～ 500 nm,and is increased for the wavelength beyond 500 nm.Rapid oxidation can decrease the surface recombination so as to increase the photovoltaic conversion quantum efficiency for the short wavelength,and it can be a guidance for increasing the efficiency of the silicon solar cells.%利用电化学方法在硅太阳能电池的金字塔上面刻蚀一层多孔硅,研究多孔硅对硅表面反射率、光电转换量子效率的影响以及氧化对不同波长的光电转换量子效率的影响.研究发现氢氟酸浓度对反射率没有明显的影响,而电化学反应时间可以调制反射率最低波长点,最终获得综合反射率低至2％的优质减反效果.多孔硅的存在使得300～500 nm的光电转换量子效率降低,500 nm以上长波的光电转换量子效率增加.氧气氛围中的快速退火能够有效降低少数载流子的表面复合,从而增加短波段的光电转换量子效率.