Lattice strain modulation toward efficient blue perovskite light-emitting diodes
Baoxing Liu, Junzi Li, Gui Wang, Fanghao Ye, Huibo Yan, Meng Zhang, Shou‐Cheng Dong, Lei Lü, Pu Huang, Tingchao He, Ping Xu, Hoi Sing Kwok, Guijun Li
Abstract
The successful implementation of perovskite light-emitting diodes (PeLEDs) in advanced displays and lighting has proven to be challenging because of the inferior performance of blue devices. Here, we point out that a strained system would lead to the quasi-degenerate energy state to enhance the excited-state transition due to the formation of double-polarized transition channel. The tensile strained structure also brings about a synergetic control of the carrier dynamics in virtue of lattice structure deformation and reduced dimensional phase regulation to promote carrier population in large bandgap domains and to realize near-unit energy transfer from the large bandgap phases to the emitter phases. Accordingly, high external quantum efficiencies of 14.71 and 10.11% are achieved for the 488- and 483-nanometer PeLEDs. This work represents a versatile strategy using a strained system to achieve enhanced radiative emission for the development of efficient PeLEDs.