Enhancing Perovskite Solar Cell Performance by Interface Engineering Using CH3NH3PbBr0.9I2.1 Quantum Dots

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• 作者：Mingyang Cha ; Peimei Da ; Jun Wang ; Weiyi Wang ; Zhanghai Chen ; Faxian Xiu ; Gengfeng Zheng ; Zhong-Sheng Wang
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：July 13, 2016
• 年：2016
• 卷：138
• 期：27
• 页码：8581-8587
• 全文大小：576K
• 年卷期：0
• ISSN：1520-5126

文摘

To improve the interfacial charge transfer that is crucial to the performance of perovskite solar cells, the interface engineering in a device should be rationally designed. Here we have developed an interface engineering method to tune the photovoltaic performance of planar-heterojunction perovskite solar cells by incorporating MAPbBr_3–xI_x (MA = CH₃NH₃) quantum dots (QDs) between the MAPbI₃ perovskite film and the hole-transporting material (HTM) layer. By adjustment of the Br:I ratio, the as-synthesized MAPbBr_3–xI_x QDs show tunable fluorescence and band edge positions. When the valence band (VB) edge of MAPbBr_3–xI_x QDs is located below that of the MAPbI₃ perovskite, the hole transfer from the MAPbI₃ perovskite film to the HTM layer is hindered, and hence, the power conversion efficiency decreases. In contrast, when the VB edge of MAPbBr_3–xI_x QDs is located between the VB edge of the MAPbI₃ perovskite film and the highest occupied molecular orbital of the HTM layer, the hole transfer from the MAPbI₃ perovskite film to the HTM layer is well-facilitated, resulting in significant improvements in the fill factor, short-circuit photocurrent, and power conversion efficiency.