Efficient Quasi-2D Perovskite Spin Light-Emitting Diodes Based on Chiral-Induced Spin Selectivity
Ruxi Zhang, Yunfei Tian, Chuying Ye, Yong Wang, Wenbo Mi, Haitao Dai, Shaolan Zou, Rui Cao, Haotian Gao, Yin Xiao
Abstract
Perovskites with spin-polarized properties are promising for realizing spin light-emitting diodes (spin-LEDs), yet achieving devices with high dissymmetry factors at room temperature remains a significant challenge due to the difficulty in creation of a nonequilibrium spin population. Here, we demonstrate a quasi-two-dimensional (2D) perovskite with spin-polarized fluorescence and its spin-LED at room temperature based on chiral-induced spin selectivity (CISS). By incorporating an achiral organic spacer in a chiral quasi- 2D film, we engineer a type II interface within the film to guarantee an effective interphase carrier transfer from the low- n chiral quantum well (QW) with a large exciton binding energy to the high- n QW. In addition, the uniformly vertically distributed chiral QW ( n = 1) with random orientations in the film is favorable for interphase carrier tunneling through organic chiral spacers and hence improved CISS efficiency. Finally, we realize a spin-LED at room temperature with a | g CP-EL | of ∼0.103. Our research reveals that instead of solely concentrating on organic chiral spacers with limited choice, employing achiral spacers to adjust the film’s energy landscape, QW distribution, and arrangement is a more effective approach to achieve CISS and spin-polarized emission in a quasi-2D perovskite film.