Origin of the Thermal Instability in CH3NH3PbI3 Thin Films Deposited on ZnO

详细信息    查看全文

• 作者：Jinli Yang ; Braden D. Siempelkamp ; Edoardo Mosconi ; Filippo De Angelis ; Timothy L. Kelly
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：June 23, 2015
• 年：2015
• 卷：27
• 期：12
• 页码：4229-4236
• 全文大小：529K
• ISSN：1520-5002

文摘

The rapid development of organometal halide perovskite solar cells has led to reports of power conversion efficiencies of over 20%. Despite this excellent performance, their instability remains the major challenge limiting their commercialization. In this report, we systematically investigate the origin of the thermal instability of perovskite solar cells fabricated using ZnO electron transport layers. Through in situ grazing incidence X-ray diffraction experiments and density functional theory calculations, we show that the basic nature of the ZnO surface leads to proton-transfer reactions at the ZnO/CH₃NH₃PbI₃ interface, which results in decomposition of the perovskite film. The decomposition process is accelerated by the presence of surface hydroxyl groups and/or residual acetate ligands; calcination of the ZnO layer results in a more thermally stable ZnO/CH₃NH₃PbI₃ interface, albeit at the cost of a small decrease in power conversion efficiency.