Yu Miao, Chen Lijia, Li Guannan, Xu Cunyun, Luo Chuanyao, Wang Meng, Wang Gang, Yao Yanqing, Liao Liping, Zhang Sam, Song Qunliang
Institute for Clean Energy and Advanced Materials, School of Materials and Energy, Southwest University Chongqing 400715 P. R. China
Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energy Chongqing 400715 P. R. China.
RSC Adv. 2020 May 21;10(33):19513-19520. doi: 10.1039/d0ra01501f. eCollection 2020 May 20.
Owing to their low cost, easy fabrication and excellent chemical stability properties, tin dioxide (SnO) nanoparticles have been widely employed as an electron transfer material in many high-efficiency perovskite solar cells (PeSCs). However, the adsorbed oxygen species ( O ) on the surface of the SnO layer, which are induced by the annealing process under ambient environment, have always been overlooked. In general, the adsorption of oxygen creates an energy barrier at the SnO/perovskite interface, impairing the efficiency of PeSCs. In this work, by using guanidinium (GA) chloride to modify the SnO surface, we have successfully improved the power conversion efficiency (PCE) of PeSCs from 15.33% (no GA-modification) to 18.46%, with a maximum fill factor of 80%. The performance enhancement is mainly attributed to the reduced energy barrier at the SnO/perovskite interface due to the strong coupling between the GA and the adsorbed oxygen, which has been supported by the FTIR and XPS results. The strategy of reducing the charge extraction barrier by GA modification has been demonstrated to be an efficient approach to improve both the PCE and stability.
由于二氧化锡（SnO）纳米颗粒成本低、易于制备且具有出色的化学稳定性，它们已在许多高效钙钛矿太阳能电池（PeSCs）中被广泛用作电子传输材料。然而，在环境气氛下退火过程中在SnO层表面诱导产生的吸附氧物种（O）一直被忽视。一般来说，氧的吸附会在SnO/钙钛矿界面处形成一个能量势垒，从而降低PeSCs的效率。在这项工作中，通过使用氯化胍（GA）对SnO表面进行改性，我们成功地将PeSCs的功率转换效率（PCE）从15.33%（未进行GA改性）提高到了18.46%，最大填充因子为80%。性能的提升主要归因于GA与吸附氧之间的强耦合降低了SnO/钙钛矿界面处的能量势垒，这已得到傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）结果的支持。通过GA改性降低电荷提取势垒的策略已被证明是提高PCE和稳定性的有效方法。
