DOI: https://doi.org/10.29363/nanoge.DEPERO.2023.028
Publication date: 14th September 2023
This contribution discusses experimental results obtained from a variety of transient optoelectronic techniques like transient photoluminescence (TRPL), transient photovoltage (TRPV), impedance spectroscopy (IS), and intensity modulated photovoltage (IMPV) applied to metal-halide materials and solar cells. While for the analysis of bare absorber films TRPL provides clear insight into the recombination kinetics of photogenerated charge carriers, this task gets more complex if the method is applied to layer stacks, including one or more contact layers. For finished devices it turns out that the amount of charge carriers extracted to the contact layers is, and should, be larger than the number of carriers that remains in the absorber. Therefore, a description of TRPL as well as of the other transient methods that can be applied to completed solar cells, needs to take into account a second independent variable, namely the number of charge carriers accumulated on the contacts of the solar cell. The resulting generic two-component model describes the experimental results, especially the fact that TRPV data exhibit an initial rise of the photovoltage followed by a decay.