Dresden 2017 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 25: Fundamentals of Perovskite Photovoltaics IV (joint session CPP/DS/HL)

CPP 25.6: Talk

Tuesday, March 21, 2017, 15:30–15:45, ZEU 222

Carrier Recombination Analysis in Perovskites Using Time- Resolved Photoluminescence — •Liudmila Kudriashova¹, Philipp Rieder¹, Kristofer Tvingstedt¹, Andreas Sperlich¹, Georgy Astakhov¹, Andreas Baumann², and Vladimir Dyakonov^1,2 — ¹Experimental Physics VI, Julius Maximilian University of Würzburg, 97074 Würzburg — ²Bavarian Center for Applied Energy Research (ZAE Bayern), 97074 Würzburg

Despite the incredible progress of perovskite-based photovoltaics, many aspects of charge carrier recombination in organometal halide perovskites still remain unclear, inhibiting the targeted production of high-performance solar cells. Under solar cell operating conditions photoluminescence (PL) in perovskites is mainly caused by recombination of free photogenerated charge carriers. Hence the time-resolved photoluminescence (TRPL) is a powerful tool to reveal the complex charge carrier behaviour in perovskite films. Here, we implement the combination of several kinetic models for TRPL in CH₃NH₃PbI₃ and CH₃NH₃PbI_3−xCl_x films to extract the characteristic recombination rates and estimate the trap concentration. We obtain trap densities in the range of 10¹⁵−10¹⁶ cm⁻³ and show that PL decay drastically depends on interfaces between the perovskite and conducting layers. Currently controversial aspects, such as different recombination pathways, origin of trap states, and the effect of photon recycling, are discussed. In summary, TRPL analysis enables the calculation of trap density and clarifies the origin of defects, which is crucial for the further development of perovskite-based photovoltaics.