Synergetic effect of organic metal compound modified SnO2 in high performance perovskite solar cells. (1st March 2022)

• Record Type: Journal Article
• Authors: Wu, Zhixing; Feng, Zhiying; Hua, Yikun; Weng, Chaocang; Chen, Xiaohong; Huang, Sumei
• Is Part Of: Solar energy. Volume 234(2022)
• Page Start: 170
• Page End: 178
• Publication Date: 2022-03-01
• Subjects: Thin-film -- Crystallization -- Perovskite -- Organic metal compound -- Defect passivation -- Stability; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2022.02.009
• Languages: English
• ISSNs: 0038-092X

Abstract

Graphical abstract: A facile and synchronous defect passivation strategy is developed by introducing ethylene diamine tetra acetic acid disodium magnesium (EDTADM) onto the SnO2 ETL surface. The best efficiency of the perovskite solar cells was improved from 16.84 % to 20.81%. Highlights: Ethylene diamine tetra acetic acid disodium magnesium (EDTADM) as a passivator. Demonstrating a facile and synchronous defect passivation strategy using EDTADM. Studying the influence of the EDTADM additive on the efficiency and the stability of the device. The champion device displaying an enhanced efficiency of 20.81% and better stability. Abstract: The various imperfections in electron transport layer (ETL), perovskite absorber and their interfaces greatly damage the efficiency, hysteresis and stability of perovskite solar cells (PSCs). Herein, we present a simultaneous defect passivation method by a novel hydrophilic organic salt, ethylene diamine tetra acetic acid disodium magnesium (EDTADM), to realize the efficient modulation of ETL, perovskite film and their interfaces. Pure SnO2 ETLs were formed by SnO2 aqueous colloidal dispersion. A trace amount of EDTADM was deposited onto SnO2 ETLs. The carboxyl and trialkylamine functionality and Mg 2+ /Na + cations of in EDTADM additive cause reduced defective and highly conductive SnO2 ETLs, which offers distinguished platforms for the growth of perovskite layers with high-quality crystallinity and compact morphologies to promote the interfacial charge transfer. The incorporation of EDTADM leads to the notable passivation through establishing coordination interactions with Sn 4+ or Pb 2+ in SnO2 and perovskite films. Moreover, Mg 2+ /Na + cations of the additive can partly get into the absorber through heat diffusion to further suppress the imperfection states, boosting the photovoltaic performance of the PSC devices. Such simultaneous optimization for SnO2 ETLs, perovskites and their interface allows the fulfillment of high power conversion efficiency (PCE) of 20.81 % with decreased hysteresis and enhanced stability for EDTADM - containing PSCs. Unsealed PSCs with EDTADM displays better ambient stability. They maintain 68 % of their original PCE after being stored under ambient condition (25–30 °C, 50–65% relative humidity) for 1300 h, while the PCE of the reference devices degrades to 28 % after the aging.