Insights Into the Local Heating Effects in Triple-Cation Mixed-Halide Perovskite Cells: Charge Dynamics, Coherent Phonons, Anion Segregation.

ABSTRACT: The behavior of triple-cation mixed halide perovskite solar cells (PSCs) under ultrashort laser pulse irradiation at varying fluences is investigated, with a focus on local heating effects observed in femtosecond transient absorption (TA) studies. The carrier cooling time constant is found to increase from 230 fs at 2 µJ cm⁻² to 1.3 ps at 2 mJ cm⁻² while the charge population decay accelerates from tens of nanoseconds to the picosecond range within the same fluence range. At fluences between 0.5 and 5 mJ cm², distinct oscillations in the TA signal (≈1.1 MHz) reveal the presence of coherent longitudinal acoustic phonons (CLAP). These phonons induce lattice strain propagating at the speed of sound through the perovskite layer and exhibit relatively long dampi

SUBMITTER: Baranowski JJ 

PROVIDER: S-EPMC11855263 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature