DOI: https://doi.org/10.29363/nanoge.almips.2021.014
Publication date: 23rd September 2021
Transient photoluminescence (trPL) characterization experiments allow to analyze charge carrier dynamics and identify the recombination channels of the device structure under investigation. Useful information that can be extracted includes the quantification of radiative and non-radiative lifetimes,[1] charge carrier extraction from differential lifetime computation[2], and the influence of the interfaces on the recombination mechanism.[3]
Fitting the experimental results with simulations further supports the analysis of the obtained data. However, qualitatively comparable fittings can be obtained with different sets of simulation parameters. In fact, in the trPL decay, the radiative and non-radiative recombination processes follow a quadratic and linear dependence on the photogenerated carriers, respectively. The carriers also depend on the incident light intensity and the doping of the emitting material. This interdependence can lead to erroneous conclusions and a robust approach to obtain simulations that are independent of the user proficiency is necessary.
Using the fully-coupled, 1-dimensional optoelectronic simulation software setfos, the trPL signal of a simple glass/perovskite structure was simulated and a routine is suggested to ascertain the reliability of the results. This routine is based on experimentally measured material properties and the analysis of the band diagram evolution during the photoluminescence transient. The validity of the simulated trPL is also recursively verified by fitting the decay with a bi-exponential function to extract the lifetimes of the recombination mechanisms.
This approach is not limited to bare perovskite and eventually, a first analysis of the influence of layer interfaces on trPL will be presented.
The mentioned routine for trPL simulation can be further extended with the inclusion of the photon recycling phenomenon.[4]
[1] Kirchartz, T.; Márquez, J. A.; Stolterfoht, M.; Unold, T. Photoluminescence‐Based Characterization of Halide Perovskites for Photovoltaics. Adv. Energy Mater. 2020, 10, 1904134.
[2] Staub, F.; Hempel, H.; Hebig, J.-C.; Mock, J.; Paetzold, U. W.; Rau, U.; Unold, T; Kirchartz, T. Beyond Bulk Lifetimes: Insights into Lead Halide Perovskite Films from Time-Resolved Photoluminescence. Phys. Rev. Appl. 2016, 6, 044017.
[3] Haddad, J.; Krogmeier, B.; Klingebiel, B.; Krückemeier, L.; Melhem, S.; Liu, Z.; Hüpkes, J.; Mathur, S.; Kirchartz, T. Analyzing Interface Recombination in Lead‐Halide Perovskite Solar Cells with Organic and Inorganic Hole‐Transport Layers. Adv. Mater. Interfaces 2020, 7, 2000366.
[4] Aeberhard, U.; Zeder, S.; Ruhstaller, B. Reconciliation of dipole emission with detailed balance rates for the simulation of luminescence and photon recycling in perovskite solar cells Opt. Express 2021, 29, 14773.