绒面ZnO/Si异质结太阳能电池的初步研究

Preliminary Study on Textured ZnO/Si Heterojunction Solar Cells

以p型单晶硅<100>作为衬底材料,通过化学腐蚀法得到硅绒面表面结构,采用喷雾热解法沉积掺Al的ZnO薄膜于绒面硅上,结合微电子光刻、磁控溅射和真空蒸镀等工艺制作上、下表面电极,于400℃氮气氛围下快速退火合金,得到Ag/Ti/n-ZnO/p-Si/Al异质结太阳能电池。对电池样品进行了原子力显微镜、霍尔效应测试、X射线衍射谱、电流电压特性等分析。得到电池最佳性能为:开路电压Voc=355 mV,短路电流Isc=36 mA,填充因子FF=0.41,电池效率达到5.2%。绒面异质结构有效降低了电池表面的光反射,相对增加了p-n结的有效面积,电池效率得到一定程度的提高。ZnO与Si界面之间SiO2层的存在是目前影响电池效率的主要因素。

p-Si 〈 100 〉 substrates were used to make textured structure in alkaline and IPA solution, ZnO ： Al thin films were deposited on textured Si substrates by ultrasonic spray pyrolysis techniques. Front and back electrode were prepared by techniques of lithography, metal sputtering and high vacuum evaporation, and subsequently annealed at a temperature of 400℃ under nitrogen environments. Atom force microscope, hall effect measurement, X-ray diffractomer and current-voltage characterization were employed to characterize solar cell performance. As a result, the conversion efficiencies of the fabricated solar cells of about 5.2% were obtained, with Voc = 355 mV, Isc = 36 mA, FF = 0.41. Textured heterojunction structure effectively reduces light reflects, increased effective p-n junction area, thus improve solar cell performance. Silicon oxide film due to oxygen diffusion at the ZnO/Si interface through the porous structure of the ZnO films were the main effect of the solar cell efficiency.