Abnormal Current–Voltage Hysteresis Induced by Reverse Bias in Organic–Inorganic Hybrid Perovskite Photovoltaics

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• 作者：Adharsh Rajagopal ; Spencer T. Williams ; Chu-Chen Chueh ; Alex K.-Y. Jen
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2016
• 出版时间：March 17, 2016
• 年：2016
• 卷：7
• 期：6
• 页码：995-1003
• 全文大小：606K
• ISSN：1948-7185

文摘

In this study, reverse bias (RB)-induced abnormal hysteresis is investigated in perovskite solar cells (PVSCs) with nickel oxide (NiO_x)/methylammonium lead iodide (CH₃NH₃PbI₃) interfaces. Through comprehensive current–voltage (I–V) characterization and bias-dependent external quantum efficiency (EQE) measurements, we demonstrate that this phenomenon is caused by the interfacial ion accumulation intrinsic to CH₃NH₃PbI₃. Subsequently, via systematic analysis we discover that the abnormal I–V behavior is remarkably similar to tunnel diode I–V characteristics and is due to the formation of a transient tunnel junction at NiO_x/CH₃NH₃PbI₃ interfaces under RB. The detailed analysis navigating the complexities of I–V behavior in CH₃NH₃PbI₃-based solar cells provided here ultimately illuminates possibilities in modulating ion motion and hysteresis via interfacial engineering in PVSCs. Furthermore, this work shows that RB can alter how CH₃NH₃PbI₃ contributes to the functional nature of devices and provides the first steps toward approaching functional perovskite interfaces in new ways for metrology and analysis of complex transient processes.