Extended Data Fig. 3: Comparison of CsPbBr3, MAPbBr3 and mixture-1.0 perovskite films.
From: Perovskite light-emitting diodes with external quantum efficiency exceeding 20 per cent
a, Estimation of trap-state density using the space-charge-limited current method, obtained using dark I–V curves of perovskite devices with the structure ITO/perovskite/Au. VTFL, trap-filled limiting voltage. b, Photographs of a pristine mixture-1.0 perovskite film (left) and a film treated by washing with IPA (right; to remove the MABr capping layer) under ultraviolet light. c, Photograph of the three perovskite films under ultraviolet light. d, Ultraviolet–visible absorbance spectra of the CsPbBr3 film and different mixture films. The black arrows indicate the disappearance of the exciton peak from the CsPbBr3 sample to the mixture-1.0 sample. e, f, Photoluminescence spectra (e) and time-resolved photoluminescence decay curves (f; excitation source: 400 nm, 4 μW) of the CsPbBr3, MAPbBr3 and mixture-1.0 films. τ is the lifetime.
