Dynamic Impact of Electrode Materials on Interface of Single-Crystalline Methylammonium Lead Bromide Perovskite

One of the current challenges in methylammonium lead halide (MAPbX(3)) perovskite application research is understanding contact formation and interfacial phenomena for highly efficient and stable device performance. For semiconductors, development of contact formation is inseparable from device performance and stability. Single-crystalline MAPbX(3) has become of great interest for perovskite devices in photodetectors, light-emitting diodes, and more recently in high-energy radiation detection. Deeper research is required to understand interfacial interactions in single-crystalline MAPbX(3). This article focuses on the dynamic impact of electrode metal (Au and Cr) on methylammonium lead bromide (MAPbBr(3)) single crystals. It is studied how charge transport properties of single crystal MAPbBr(3) can be tuned via electrode material selection at the metal/MAPbBr(3) interface to improve device performance with proper contact formation. The ability to create an ohmic-like or nonohmic contact by switching the electrode metal from Cr to Au, respectively, is demonstrated. It is observed that the interfacial charge transfer resistance (recombination resistance) of the Cr/MAPbBr(3) interface is 1.79 x 10(9), compared to 1.32 x 10(7) for the Au/MAPbBr(3). Cr contacts can reduce hysteretic behavior by reducing interfacial recombination and interfacial polarization. These studies provide insight to metal/MAPbX(3) interfacial interactions toward device engineering for hole transport layer-free MAPbX(3) device structures.