Defect trapping states and charge carrier recombination in organic–inorganic halide perovskites

Abstract

The defect density and relaxation rate in organic–inorganic perovskites dominate the carrier recombination dynamics and thus PL intensity exhibits super-linear increase with increasing excitation.

Acoustic-optical phonon up-conversion and hot-phonon bottleneck in lead-halide perovskites

“…This significant difference is believed to be caused by the lattice defects. Our previous observation confirms that the MAPbI 3 sample prepared by the gas-assisted method (see ‘Methods' section) has a large density of sub-band-gap trapping states39. The fast carrier relaxation observed here convinces us that a large number of above-band-gap defects are also presented in this sample, which could provide more relaxation pathways for the hot carriers40.…”

Stacking‐Layer‐Number Dependence of Water Adsorption in 3D Ordered Close‐Packed g‐C3N4 Nanosphere Arrays for Photocatalytic Hydrogen Evolution

“…[14] Figure 4a shows photoluminescence (PL) spectra of the different samples.H ere,C Ns hows as trong emission peak, suggesting ah igh charge recombination rate for bulk g-C 3 N 4 .With the construction of nanosphere arrays and the introduction of point defect cavities,t he PL fluorescence of the CNAs was quenched with varying degrees, indicating the structure-induced advantages of the CNAs for charge transfer. [17] These results are also confirmed by the fluorescence decay spectra. This phenomenon may be associated with the fact that the main PL emission centers could be distributed on the interior of the CNAsamples,which are separated from the surface reaction sites endowed by the point defect cavities.…”

Time-resolved fluorescence anisotropy study of organic lead halide perovskite

“…Free electron-hole recombination is dominant in sample S1, indicate the high quality with minimized defect trapping, similar to the published reports [41]. In contrast, a fast component appears in the PL decay curve in S4 due to the Shockley-Read-Hall (SRH) recombination via sub-bandgap trap states [48]. The lifetime of S6 is much shorter compared with S1 and S4 because of the intrinsic electron-hole recombination [43].…”