Improved performance of CsPbBr3 perovskite light-emitting devices by both boundary and interface defects passivationElectronic supplementary information (ESI) available: XPS, PL spectra, ATR-FTIR spectra, XRD patterns, capacity density, SEM images, and work function for PEDOT:PSS films; optical and electrical performances for PeLED with CB:DMSO treated PEDOT:PSS, device stability, additional tables. See DOI: 10.1039/c8nr06311g

Significantly enhanced luminance and current efficiency for inorganic light-emitting devices have been obtained by tetrabutylammonium bromide (TBAB) additive into perovskite precursors. Reduced nonradiative defects primarily passivated by TBAB and increased exciton binding energy are responsible for improvement of PeLED performance. By employing a TBAB-treated interfacial layer, interface defects are reduced and it results in further promotion of electroluminescence performance of PeLED, including turn-on voltage of 2.6 V, brightness as high as 67 300 cd m −2 , current efficiency of 22.5 cd A −1 and external quantum efficiency of 6.28%. Our results shed light on optimization of inorganic PeLEDs by focusing on the removal of defects both at the grain boundaries and the interfaces between carrier transport layers and perovskite emitting layers. Significantly enhanced luminance and current efficiency for inorganic light-emitting devices have been obtained by tetrabutylammonium bromide (TBAB) as both additive into perovskite precursors and interface modification.