采用超高频等离子增强化学气相沉积(VHF-PECVD)技术,逐次高速沉积非晶硅顶电池及微晶硅底电池,形成pin/pin型非晶硅/微晶硅叠层电池.通常顶电池的n层与底电池的p层均采用微晶硅材料来形成隧穿复合结,然而该叠层电池的光谱响应测试结果表明,顶电池存在着明显的漏电现象.针对该问题作者提出,在顶电池的微晶硅n层中引入非晶硅n保护层的方法.实验结果表明,非晶硅n层的引入有效地改善了顶电池漏电的现象;在非晶硅n层的厚度为6nm时,顶电池的漏电现象消失,叠层电池的开路电压由原来的1.27提高到1.33V,填充因子由60%提高到63%.
Pin/pin "micromorph" tandem solar cells were deposited by very high frequency plasma enhanced chemical vapor deposi- tion (VHF-PECVD). Tunnel recombination junctions of the "micromorph" tandem solar ceils consisting of two microcrystalline- doped layers with a defect rich interface were developed. While the solar ceils performed reasonably well under AM 1.5 lights, we found through spectral response measurements that the first deposited cell of the tandem structures was leaking under low light condi- tions. The insertion of a thin protection layer of n-type amorphous silicon is presented in this paper. The results shown that the intro- duced n-type amorphous silicon could improve the leakage phenomenon. The leakage phenomenon disappeared when the thickness of the n-type amorphous silicon was 6nm,leading to an increase in open-circuit voltage. The open-circuit voltage increased from 1.27 to 1.33V and FF increased from 60% to 63%.