Organic–Inorganic Perovskite Light‐Emitting Electrochemical Cells with a Large Capacitance. (2nd November 2015)

• Record Type: Journal Article
• Authors: Zhang, Huimin; Lin, Hong; Liang, Chunjun; Liu, Hong; Liang, Jingjing; Zhao, Yong; Zhang, Wenguan; Sun, Mengjie; Xiao, Weikang; Li, Han; Polizzi, Stefano; Li, Dan; Zhang, Fujun; He, Zhiqun; Choy, Wallace C. H.
• Is Part Of: Advanced functional materials. Volume 25:Number 46(2015)
• Page Start: 7226
• Page End: 7232
• Publication Date: 2015-11-02
• Subjects: current–voltage hysteresis -- light‐emitting electrochemical cells -- organic–inorganic halide perovskites -- solid electrolytes; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201502962
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract : While perovskite light‐emitting diodes typically made with high work function anodes and low work function cathodes have recently gained intense interests. Perovskite light‐emitting devices with two high work function electrodes with interesting features are demonstrated here. Firstly, electroluminescence can be easily obtained from both forward and reverse biases. Secondly, the results of impedance spectroscopy indicate that the ionic conductivity in the iodide perovskite (CH3 NH3 PbI3 ) is large with a value of ≈10 −8 S cm −1 . Thirdly, the shift of the emission spectrum in the mixed halide perovskite (CH3 NH3 PbI3− x Br x ) light‐emitting devices indicates that I − ions are mobile in the perovskites. Fourthly, this work shows that the accumulated ions at the interfaces result in a large capacitance (≈100 μF cm −2 ). The above results conclusively prove that the organic–inorganic halide perovskites are solid electrolytes with mixed ionic and electronic conductivity and the light‐emitting device is a light‐emitting electrochemical cell. The work also suggests that the organic–inorganic halide perovskites are potential energy‐storage materials, which may be applicable in the field of solid‐state supercapacitors and batteries. Abstract : Light‐emitting electrochemical cells (LECs) of organic–inorganic perovskite (CH3 NH3 PbI3 ) with two high work function electrodes are demonstrated. Results indicate that CH3 NH3 PbI3 has an ionic conductivity of ≈10 −8 S cm −1 . The accumulated ions at the interfaces result in a large capacitance, which suggests a potential application in electrochemical energy‐storage devices, such as solid‐state supercapacitors and batteries.