Modeling of Charge Injection, Recombination, and Diffusion in Complete Perovskite Solar Cells on Short Time Scales

Area of Science:

• Materials Science
• Photovoltaics
• Physical Chemistry

Background:

• Perovskite solar cells (PSCs) are promising photovoltaic devices.
• Understanding charge carrier dynamics is crucial for optimizing PSC efficiency.
• Ultrafast optical pulse excitation is a key technique for probing these dynamics.

Purpose of the Study:

• To develop a comprehensive model for charge population decay in working PSCs.
• To identify optimal experimental and analytical methodologies for characterizing charge transfer dynamics.
• To determine key parameters governing charge transfer on picosecond and nanosecond timescales.

Main Methods:

• Numerical simulations of a charge decay model incorporating injection, diffusion, and recombination.
• Validation using broadband transient absorption spectroscopy on mixed halide, triple-cation perovskite.
• Analysis of experimental data under varying bias potentials and pump fluences.

Main Results:

• The proposed model accurately describes charge population decay.
• Simulation results are consistent with experimental transient absorption data.
• Key parameters governing charge transfer dynamics were identified.

Conclusions:

• The combined modeling and experimental approach provides a robust method for analyzing PSCs.
• Optimal measurement conditions (bias, fluence) and analysis techniques were established.
• This work advances the understanding of charge transfer processes in efficient perovskite solar cells.