Yingguo Yang

Abstract Despite huge progress accomplished in perovskite light-emitting diodes (PeLEDs), the electroluminescence performance of blue PeLEDs lags far behind, constraining the widespread application of PeLED technology for vibrant full-colour displays1,2,3,4,5. The wider bandgaps of blue emitters require higher working voltages of corresponding electroluminescent devices, intensifying the octahedral instability of perovskites with ionic nature6,7.

Abstract Molecular additives are frequently employed to enhance the performance of perovskite light-emitting diodes (PeLEDs), either through surface defect passivation or crystal growth control. In general, such passivation is attained through the chelation of the molecular additive to a defective Pb site along a lattice plane. Unfortunately, nano-crystallites often display multiple lattice planes and defects that a single additive is inadequate in passivating.

Abstract Directional light emitters are vital to enhancing the out-coupling efficiency of light-emitting devices. Having asymmetric atomic arrangements or crystalline structures is an important precondition for being directional light emitters; therefore, it is theoretically impossible to achieve directional light emission in quasi-spherical quantum dots with isotropic crystalline structures, such as zinc-blende.