Proceedings of nanoGe September Meeting 2015 (NFM15)
Publication date: 8th June 2015
The surge of organic-inorganic lead halide perovskites with very large efficiency, has opened up the ineterst to understand the operation of the solar cell, in terms of physical photovoltaic processes. Apart from the remarkable bulk properties of this class of semiconductors, it has been realized that the contacts are a key aspect of the operation and show dynamic interactions. Here we approach the question of contacts in perovskite solar cell utilizing a broad set of experimental results, and we discuss the physical properties including the modiffication of barrier promoted by transformation of ionic deffects in the vicinity of the interface. Important points for this analysis is the measurement of capacitances by impedance spectroscopy, the observation of hysteresis and reversal of JV curves, and the detailed energy diagram that can be obtained from Kelvin probe mapping. We also discuss the modeling of ionic defect properties that may govern ion diffusion nad barrier transformation.