ScholarWorks@숙명여자대학교

초록

Perovskite light-emitting diodes (LEDs) have received significant attention for their use in next-generation displays and optical sensors. Methylammonium lead bromide (MAPbBr(3)) emissive layers exhibit excellent green luminance characteristics. However, their bottom-up synthesis from precursor films poses a critical bottleneck in enhancing the device performance and stability. In particular, the intrinsic formation of three-dimensional (3D) MAPbBr(3) crystals degrades the luminance owing to suppressed radiative recombination due to their dense charge-trap sites. In this study, we prepared PbBr2(DMSO)(2) complex precursors by recrystallization. Bimodal growth on 3D/nanocrystals was achieved by the rapid crystallization of MAPbBr(3) through intermolecular exchange between MABr and dimethyl sulfoxide (DMSO). The undercoordination of DMSO molecules to Pb2+ assisted in the rapid and uniform reactions of MABr and PbBr2. The resulting morphologies exhibited nanocrystalline layers surrounding the 3D crystals. Owing to the reduced defect density and improved carrier mobility in the emissive layers, the devices achieved an outstanding maximum luminance of 10,403.6 cd m(-2), a current efficiency of 22.93 cd A(-1), and an external quantum efficiency of 7.11%. Furthermore, the normalized electroluminance intensity of the encapsulated devices was retained at 85.7% of its initial value after 60 min.

키워드