高效非晶硅叠层太阳电池的优化设计

THE OPTIMUM DESIGN OF HIGH EFFICIENCY a-Si TANDEM SOLAR CELLS

研究了高效ａ－Ｓｉ／ａ－Ｓｉ／ａ－ＳｉＧｅ三结太阳电池的优化设计。电流匹配是影响二端子叠层太阳电池填充因子的关键因素，在内电极的Ｐ／ｎ界面处附加载流子复合是由少数载流于浓度、界面态和Ｐ／ｎ界面处材料的几何因素匹配决定的。利用适当的带隙匹配和ｉ层厚度匹配来实现ａ－Ｓｉ／ａ－Ｓｉ／ａＳｉＧｅ三结太阳电池结构的最佳化，同时采用改善ｎ／ｉ界面特性的缓冲层技术；获得了Ｖｏｃ＝２．４８Ｖ、Ｊｓｃ＝６．５８ｍＡｃｍ－２、ＦＦ＝７０．４％、在ＡＭＩ光照下转换效率为１１．５％的ａ－Ｓｉ／ａ－Ｓｉ／ａ－ＳｉＧｅ三结叠层太阳电池。

In this paper, the optimum design of high efficiency a-Si/a-Si/a-SiGe triple-junctim solor cells is invetigated in detail.Our results show that curremt matching is one of key factors effecting the fill factor of two-terminal tandem solar cells and the excess carrier recombinatim at p/n interface acted an internal electrode is dominated by tile density of the minority carriers. interfacial states and geometrical factor match of the materials at the p/n interface.In this work. the suitabhe bandgap matching and i-layer thickness matching are used to optimum the structure of a-Si/a--Si/a--SiGe triple-junction solar cells and at the same time. using the buffer layer for improving the n/i interface properties. the a-Si/a-Si/a-Si Ge triple-junction solar cells with conversion efficiency of 11.5% (Vo c =2. 48V. Jsc = 6.58mAcm-2 and FF =70. 4%) has been obtained under AM 1 (100mWcm-2) illumination.