Fig. 2
From: Indirect tail states formation by thermal-induced polar fluctuations in halide perovskites
The PL properties of the MAPbBr3 polycrystalline (PC) films prepared with different precursor concentrations. a PL profiles of the MAPbBr3 PC thin films prepared with 0.25, 0.5, 0.75, and 1 M precursor concentrations. b Temperature-dependent PL peak positions for the film prepared with 1 M precursor concentration. This concentration matches that used for single crystal growth. The film has a thickness of around 220 nm. c Schematic of different PL excitation and collection geometries for the MAPbBr3 thin films as described in the main text. d PL profiles with different excitation and collection schemes as well as fittings of the PL profiles by only considering the reabsorption effect in MAPbBr3 thin films. e The pseudo-color mapping of the PL intensity versus time and wavelength at 165 K (left) and the deconvolved peaks using non-negative matrix factorization method (right). f The deconvolved PL kinetics at 165 K and the global PL kinetics at room temperature (295 K)
