Xing Zhenning, Ou Bing, Sun Hao, Di Haipeng, Jin Yingrong, Xiong Ying, Liao Feiyi, Zhao Yiying
Institute of Materials, China Academy of Engineering Physics, Jiangyou 621908, China.
School of Materials Science and Engineering, Xihua University, Chengdu 610039, China.
ACS Omega. 2023 May 27;8(23):20912-20919. doi: 10.1021/acsomega.3c01694. eCollection 2023 Jun 13.
The low electrical conductivity and the high surface defect density of the TiO electron transport layer (ETL) limit the quality of the following perovskite (PVK) layers and the power conversion efficiency (PCE) of corresponding perovskite solar cells (PSCs). Sulfur was reported as an effective element to passivate the TiO layer and improve the PCE of PSCs. In this work, we further investigate the effect of chemical valences of sulfur on the performance of TiO/PVK interfaces, CsFAMA PVK layers, and solar cells using TiO ETL layers treated with NaS, NaSO, and NaSO, respectively. Experimental results show that the NaS and NaSO interfacial layers can enlarge the grain size of PVK layers, reduce the defect density at the TiO/PVK interface, and improve the device efficiency and stability. Meanwhile, the NaSO interfacial layer leads to a smaller perovskite grain size and a slightly degraded TiO/PVK interface and device performance. These results indicate that S can obviously improve the quality of TiO and PVK layers and TiO/PVK interfaces, while SO has little effects, even negative effects, on PSCs. This work can deepen the understanding of the interaction between sulfur and the PVK layer and may inspire further progress in the surface passivation field.
TiO电子传输层（ETL）的低电导率和高表面缺陷密度限制了后续钙钛矿（PVK）层的质量以及相应钙钛矿太阳能电池（PSC）的功率转换效率（PCE）。据报道，硫是一种钝化TiO层并提高PSC的PCE的有效元素。在这项工作中，我们分别使用经NaS、NaSO和NaSO处理的TiO ETL层，进一步研究硫的化学价对TiO/PVK界面、CsFAMA PVK层和太阳能电池性能的影响。实验结果表明，NaS和NaSO界面层可以增大PVK层的晶粒尺寸，降低TiO/PVK界面处的缺陷密度，并提高器件效率和稳定性。同时，NaSO界面层导致钙钛矿晶粒尺寸较小，TiO/PVK界面和器件性能略有下降。这些结果表明，S可以显著提高TiO和PVK层以及TiO/PVK界面的质量，而SO对PSC几乎没有影响，甚至有负面影响。这项工作可以加深对硫与PVK层之间相互作用的理解，并可能推动表面钝化领域的进一步发展。
