Double‐layered SnO2/NH4Cl‐SnO2 for efficient planar perovskite solar cells with improved operational stability. Issue 9 (16th March 2021)

• Record Type: Journal Article
• Authors: Song, Peiquan; Shen, Lina; Zheng, Lingfang; Liu, Kaikai; Tian, Wanjia; Chen, Jingfu; Luo, Yujie; Tian, Chengbo; Xie, Liqiang; Wei, Zhanhua
• Is Part Of: Nano select. Volume 2:Issue 9(2021)
• Page Start: 1779
• Page End: 1787
• Publication Date: 2021-03-16
• Subjects: electron transport double layer -- operational stability -- perovskite solar cell -- tin oxide; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.5
• DOI: 10.1002/nano.202000306
• Languages: English
• ISSNs: 2688-4011

Abstract

Abstract: Tin oxide (SnO2 ) is widely used as an electron transport layer (ETL) to fabricate planar perovskite solar cells (PSCs) due to their easy and low‐temperature processed fabrication. Enhancing carrier extraction and energy level alignment at the perovskite/SnO2 interface is vital to improve the device performance further. Here, we demonstrate a double‐layered SnO2 / NH4 Cl‐SnO2 as an efficient ETL. The top NH4 Cl‐SnO2 shows a better energy level alignment with the perovskite and reduced alkalinity to avoid perovskite degradation, resulting in enhanced electron extraction efficiency and interfacial stability. Furthermore, the bottom SnO2 retains the capability of efficient carrier transport to avoid charge accumulation. As a result, we achieve a champion device with a power conversion efficiency of 21.01% and negligible hysteresis. Moreover, the corresponding PSCs show much improved operational stability, retaining 80% of the initial efficiency after 1090 hours of operation at the maximum power point under 1‐sun illumination. While the pristine SnO2 based PSCs only insist on 278 hours before losing 20% of the initial efficiency. Abstract : Double‐layered SnO2 /NH4 Cl‐SnO2 is used as an electron transport layer to fabricate efficient planar perovskite solar cells. The NH4 Cl‐SnO2 top layer enables efficient electron extraction, and the SnO2 bottom layer facilitates charge transport. Perovskite solar cell based on this functionalized electron transport layer delivers power conversion efficiency of 21.01% and an operational lifetime of over 1090 hours.