Regensburg 2016 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 80: Hybrid and Perovskite Photovoltaics IV (Joint session of CPP, DF, DS and HL, organized by HL)

HL 80.4: Talk

Thursday, March 10, 2016, 15:30–15:45, H2

J-V Hysteresis Observed in Methylammonium Lead Halide Perovskite Films at Different Voltage Scales — •Martina Stumpp, Raffael Ruess, Jonas Horn, Jan Tinz, Christoph Richter, and Derck Schlettwein — Justus-Liebig-Universität Gießen, Institut für Angewandte Physik, Heinrich-Buff-Ring 16, D-35392 Gießen, GERMANY

Hysteresis in the current-voltage curves of methylammonium lead halide films deserves detailed investigation because it can affect their applicability in perovskite solar cells. In the current study, J-V hysteresis of CH₃NH₃PbI₃ and CH₃NH₃Pb(I_0.95Br_0.05)₃ prepared via different established deposition techniques was studied in a symmetric contact geometry of microstructured gold electrode arrays on SiO₂/Si wafers. The measured J-V characteristics showed a different behavior of hysteresis depending on the applied voltage range. Residual currents at zero applied bias were observed following positive or negative poling showing persistent polarization of the perovskite films. At higher bias voltages, additional inverted hysteresis loops were measured pointing at a decrease in barrier height and width at blocking perovskite/metal contacts, presumably caused by migrating iodide ions. The net J-V characteristics in this voltage range can be simulated by two diodes operated back-to-back. Time-dependent studies were performed to analyze the decay of the different observed polarization phenomena in the films during either short-circuit or continuous sweeping of the bias.