Fig. 5
From: Multi-inch single-crystalline perovskite membrane for high-detectivity flexible photosensors
Optical properties of (PEA)2PbI4 SCM. a The absorbance spectrum and corresponding Tauc plot of the (PEA)2PbI4 SCM showing a band gap 2.27 eV. The inset shows the photograph of the (PEA)2PbI4 SCM used for absorbance measurement. b Ultraviolet photoemission spectroscopy (UPS) of the (PEA)2PbI4 SCM. Insets: energy band diagram for the (PEA)2PbI4 SCM. c Photoluminescence spectrum of the (PEA)2PbI4 SCM and MCTF excited at 375 nm. Inset: the photo of the (PEA)2PbI4 SCM and MCTF excited at 375 nm. d, e Photographs of the (PEA)2PbI4 SCM under weak room light and strong UV lamp. f Time-resolved PL of the (PEA)2PbI4 SCM and MCTF at 525 nm. The excitation laser beam wavelength is 375 nm. Inset: Photograph of the green photoluminescence of a (PEA)2PbI4 SCM (left) and MCTF (right) excited by a 375 nm laser beam. g 3D excitation–emission plot for the (PEA)2PbI4 SCM. Emission intensity rises with the color changing from blue to green and red. h Evolution of the photoluminescence spectrum shown using pseudocolor plot, indicating consistent emission peak wavelength and intensity across the large area
