Bias stress effects in organic-inorganic halide perovskites

The power conversion efficiencies of organic-inorganic halide perovskites (OIHP) have been improved over the last decade using a wide variety of methods, such as composition manipulation, dopant introduction, and interfacial buffers. These methods, however, have taken little regard for the electronic and interfacial effects such alterations may cause within devices under voltage bias stress. A condition required for most device operation. Using two efficient and commonly studied OIHP compositions, CH₃NH₃PbI_2.87Cl_0.13 and Cs_0.1(MA_0.17FA_0.83)_0.9Pb(I_0.83Br_0.17)₃, we investigate the effect of halide and cation substitution in OIHP structures to understand the unique current behavior while under a range of voltage bias stress in both light and dark conditions. With the use of a second device structure, without transport layers, the same bias stress effects unique for the different OIHP structures are observed. Confirming the difference in the current trends, for the two materials, is due to intrinsic behavior of the perovskite material itself, rather than the interfacial recombination and interactions with the transport layers. In this study, we continue to flush out how the changes in morphological defects and ion migration in the two OIHP materials are influencing charge transport.