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.