Since its first report in 2009,CH_3NH_3PbI_3-based perovskite solar cells(PSCs)have emerged as one of the most exciting developments in the next generation photovoltaic(PV)technologies[1],with its PV conversion efficiency(PCE)rising spectacularly from3.81% to 22.1% in just 7 years.Such rapid advance is
高效的电子选择层对提高有机金属卤化物基钙钛矿太阳电池的能量转换效率起着至关重要的作用.本文采用低温100°C旋转涂膜和无后续高温烧结的方法制备了高结晶度的纳米氧化锡薄膜,利用瞬态时间分辨荧光光谱测试对SnO_2/CH_3NH_3PbI_3薄膜进行分析发现,这种低温氧化锡薄膜与相同条件下制备的低温氧化钛薄膜相比,具有更高的荧光淬灭和电子抽取能力.电流-电压曲线表明,低温氧化锡基钙钛矿太阳电池具有优异的光电转换性能,其开路电压为0.91 V,短路电流密度为20.73 mA cm^(–2),填充因子为64.25%,其器件光电转换效率达到12.10%,高于低温二氧化钛基器件的光电转换效率7.16%.上述无高温烧结的旋转涂膜方法为制备低温大面积钙钛矿太阳电池提供了一种研究思路.
The energy band-gap and related factors of tantalum pentoxide with hexagonal phase were investigated using hybrid functional B3 LYP and s X-LDA methods. The results showed that both s X-LDA and B3 LYP techniques reveal the indirect semiconductor nature of δ-Ta2O5, whereas the obtained value of energy band-gap is much higher than previous theoretical reports but closer to the experimental data. The optical bandgap of δ-Ta2O5 is expected to originate from the O 2p→Ta 5d transition which may benefit from the d-s-p hybridization.
