Fig. 6
Device structure of PeLEDs. a Device structure and a corresponding cross-sectional TEM image of the multi-layer PeLEDs: ITO/PEDOT:PSS (40 nm)/CsPbBr3 (200 nm)/TPBI (20 nm)/LiF (1 nm)/Al (100 nm). b Schematic flat-band energy diagram of the PeLED; the energy levels for PEDOT:PSS and TPBI are taken from reference6. c Normalized PL spectrum of the CsPbBr3 film, and EL spectrum of the PeLED at an applied voltage of 5.5 V. Inset: The photograph of the operating device with an emitting area of 2 mm × 2 mm. d J–V hysteresis of PeLEDs based on CsBr(1.7)- and CsTFA(1.7)-derived CsPbBr3 perovskite films
