A New Framework for Understanding Recombination-Limited Charge Extraction in Disordered Semiconductors

• DOI: 10.1021/acs.jpclett.4c00218
• Publication Date: 2024-04-16T20:18:08Z
• Authors: Austin M. Kay; Drew B. Riley; Paul Meredith; Ardalan Armin; Oskar J. Sandberg

Recombination of free charges is a key loss mechanism limiting the performance organic semiconductor-based photovoltaics such as solar cells and photodetectors. The carrier density-dependence rate recombination associated coefficients are often estimated using transient charge extraction (CE) experiments. These experiments, however, neglect effect during process. In this work, validity CE experiment for low-mobility devices, photovoltaics, investigated drift-diffusion simulations. We find that leads to incomplete CE, resulting in density-dependent constants overestimated orders; an depends on both mobilities resistance-capacitance time constant. To overcome intrinsic limitation experiment, we present analytical model accounts recombination, validate it numerical simulations, employ correct observed experimentally determined bimolecular constants.