Proceedings of MATSUS Spring 2024 Conference (MATSUS24)
DOI: https://doi.org/10.29363/nanoge.matsus.2024.380
Publication date: 18th December 2023
Interfacial charge carrier recombination is currently one of the major performance bottlenecks in single- and multi-junction metal halide perovskite (MHP) solar cells. In our work, we investigate interfacial charge carrier recombination processes in state-of-the-art MHP thin films and device structures by transient spectroscopies including transient reflection, transient absorption, time-resolved photoluminescence, and time-domain terahertz spectroscopy across a wide dynamic range from femto- to microseconds. The MHPs investigated are multi-cation (mixed) halide perovskites as neat MHP thin films, passivated MHP thin films, perovskite films adjacent to charge transport layers (CTLs), MHP films adjacent to CTLs with additional interlayers (ITLs) and in the presence of electrodes, as well as MHP films on transparent conductive oxides (TCOs) with and without common self-assembled monolayers (SAMs). Organic CTLs are also used, since they allow direct probing of the carrier dynamics in the CTL (not only in the perovskite film), thereby allowing to distinguish between carrier extraction and interfacial recombination. Our spectroscopic experiments are supported by computational studies providing insight into the role of (bulk and surface/interface) defects on carrier recombination, the chemistry of defect passivation at interfaces, and interfacial carrier extraction and recombination dynamics. Our studies provide in-depth insight into interfacial charge carrier recombination processes at various types of interfaces in perovskite devices and reveal pathways to mitigate those losses to enhance the device Voc and quantum efficiency in both single- and multijunction photovoltaic solar cells.
This presentation is based upon work supported by King Abdullah University of Science and Technology (KAUST) under Award No. ORA-CRG10-2021-4681.