Fig. 7: Optical-pump terahertz-probe spectroscopy in MAPbI3-xClx and FAPb(BryI1-y)3 perovskite films.
From: Advanced spectroscopic techniques for characterizing defects in perovskite solar cells

a Normalized THz photoinduced absorption spectra of vapor-deposited CH3NH3PbI3-xClx films for time-delays 20 ps and 2 ns (excitation at 550 nm with pulse fluence 280 µJ cm−2). Reproduced with permission66. Copyright 2014, The Royal Society of Chemistry. b THz photoconductivity transients of four compositions of FAPb(BryI1-y)3 for excitation fluences ranging from 8 to 65 µJ cm−2 at 400 nm wavelength; the initial decay components of the photoconductivity transients gradually become faster on increasing the bromide content in the films. Reproduced with permission from ref. 67, copyright (Springer Nature, 2021).