In a study published in ACS Applied Materials & Interfaces, a research group led by GUO Xiaoyang from the Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) of the Chinese Academy of Sciences (CAS) developed a new method to achieve high-efficiency perovskite light-emitting diodes by tuning the low-dimensional phase composition.

A quasi-two-dimensional perovskite structure with high exciton binding energy can be formed by dimension reduction strategy, which can greatly improve the electroluminescence efficiency. However, the complex low-dimensional phase distribution problem in quasi-two-dimensional perovskite was the key obstacle to further improve its efficiency.

GUO's team generated a cesium lead bromide (CsPbBr₃) perovskite luminescent film with a mixed distribution of two-dimensional and three-dimensional phases by doping the organic additive diethylammonium bromide, and constructed a two-dimensional/three-dimensional heterojunction perovskite structure.

The formation of low-dimensional phase helped to improve film morphology and luminescent properties. At the same time, the formation of heterojunctions effectively avoided the spectrum broadening and multi-peaks luminescence caused by the complex distribution of low-dimensional phases, and helped to improve the performance of perovskite light-emitting devices.

Depends on two-dimensional/three-dimensional heterojunction structure, the external quantum efficiency of the all-inorganic component perovskite light-emitting diode was 9.6%, and the maximum brightness of the device reached 32500 cd/m².

This study provided a simple and effective strategy to realize high-efficiency perovskite light-emitting diodes by utilizing low-dimensional phase composition, further promoting commercial applications of perovskite light-emitting diodes.