The zero-dimensional all-inorganic perovskites are self-activated blue emitters with slight hygroscopicity, scalable synthesis, and high radiation detection efficiency.

This paper reports a new method to generate stable and high-brightness electroluminescence (EL) by subsequently growing large/small grains at micro/nano scales with the configuration of attaching small grains on the surfaces of large grains in perovskite (MAPbBr 3) films by mixing two precursor solutions (PbBr 2 + MABr and Pb(Ac) 2 $3H 2 O + MABr). Consequently, the small and large grains serve, respectively, as passivation agents and light-emitting centers, enabling self-passivation on the defects located on the surfaces of light-emitting large grains. Furthermore, the light-emitting states become linearly polarized with maximal polarization of 30.8%, demonstrating a very stable light emission (49,119 cd/m 2 with EQE = 11.31%) and a lower turn-on bias (1.9 V) than the bandgap (2.25V) in the perovskite LEDs (ITO/PEDOT:PSS/MAPbBr 3 /TPBi[50 nm]/LiF[0.7 nm]/Ag). Therefore, mixing large/ small grains with the configuration of attaching small grains on the surfaces of large grains by mixing two precursor solutions presents a new strategy to develop high-performance perovskite LEDs.

No abstract