Enhanced Electronic Properties of SnO2 via Electron Transfer from Graphene Quantum Dots for Efficient Perovskite Solar Cells
Enhanced Electronic Properties of SnO2 via Electron Transfer from Graphene Quantum Dots for Efficient Perovskite Solar Cells
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DOI：
10.1021/acsnano.7b04070
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发表时间：
2017-09-01
期刊：
影响因子：
17.1
通讯作者：
Yang, Deren
中科院分区：
文献类型：
--
作者：
Xie, Jiangsheng;Huang, Kun;Yang, Deren
二氧化锡（SnO 2）已被证明是获得高性能钙钛矿太阳能电池（PSC）的有效电子传输层（ETL）。然而，低温溶液处理的SnO 2中的大量陷阱态将降低PSC的性能并导致严重的滞后。在这里，我们报告了一种策略，以提高电子性能的SnO 2通过一个简单的处理的薄膜添加少量的石墨烯量子点（GQD）。我们证明了GQD中的光生电子可以转移到SnO 2的导带。从GQD转移的电子将有效地填充电子陷阱以及提高SnO 2的导电性，这有利于提高电子提取效率和减少ETL/钙钛矿界面处的复合。用SnO 2：GQD制造的器件可以达到19.2 +/- 1.0%的平均功率转换效率（PCE）和20.23%的最高稳态PCE，具有非常小的滞后。我们的研究提供了一种有效的方法来提高钙钛矿太阳能电池的性能，通过改善SnO 2的电子性质。
Tin dioxide (SnO2) has been demonstrated as an effective electron-transporting layer (ETL) for attaining high-performance perovskite solar cells (PSCs). However, the numerous trap states in low-temperature solution processed SnO2 will reduce the PSCs performance and result in serious hysteresis. Here, we report a strategy to improve the electronic properties in SnO2 through a facile treatment of the films with adding a small amount of graphene quantum dots (GQDs). We demonstrate that the photogenerated electrons in GQDs can transfer to the conduction band of SnO2. The transferred electrons from the GQDs will effectively fill the electron traps as well as improve the conductivity of SnO2, which is beneficial for improving the electron extraction efficiency and reducing the recombination at the ETLs/perovskite interface. The device fabricated with SnO2:GQDs could reach an average power conversion efficiency (PCE) of 19.2 +/- 1.0% and a highest steady-state PCE of 20.23% with very little hysteresis. Our study provides an effective way to enhance the performance of perovskite solar cells through improving the electronic properties of SnO2.