Improved Performance for Thermally Evaporated Perovskite Light-Emitting Devices via Defect Passivation and Carrier Regulation

Efficient inorganic perovskite light-emitting devices (PeLEDs) with a vacuum-deposited CsPbBr₃ emission layer were realized by introducing an ultrathin 2-phenylethanamine bromide interlayer. The PEA⁺ cations not only passivated the nonradiative defects by terminating on the CsPbBr₃ surface but also regulated the charge transport to balance the hole and electron transport. Consequently, the PeLEDs exhibit significantly promoted performance with a turn-on voltage of 3 V, a maximum current efficiency of 14.64 cd A^–1, and an external quantum efficiency of 4.10%. Our work would provide instructive guidance for realizing efficient PeLEDs based on a vacuum processing method via focusing on the interface modification between the perovskite layer and the carrier transport layer.