Employing metal halide perovskite to enable carbon dots-based LEDs

Modern optoelectronic devices, such as solar cells and LEDs, commonly rely on organic charge transport layers to either extract or inject charges. Next-generation carbon dots-based LEDs would also depend on these charge transport layers to supply enough charges, but existing organic materials are unable to fulfill this need.

Tan et al. outlined a new material based on metal halide perovskite that can be used in place of organics as a charge transport layer. The high charge mobility of the perovskite adequately meets the demand of the next-generation LEDs.

“In this work, for the first time, we demonstrate that metal halide perovskite can be employed as a new class of interfacial charge-transport materials in fabricating high-efficiency carbon dots-based LEDs,” said author Zhan’ao Tan.

The team used their metal halide perovskite transport layer achieve a maximum luminance and current efficiency comparable with the best existing carbon dots-based LEDs. They are hopeful the layer will be useful as a low-cost, high-performing alternative to existing materials.

The team is now looking to expand the flexibility of their system and the range of materials that it can employ.

“This work is just a beginning and demands more attempts and in-depth studies to break through the limitations in future research,” said Tan. “For future research to be successful, we are planning to address the issue of poor compatibility between alcohol-soluble carbon dots and perovskite, fabricate solid-state fluorescent carbon dots to avoid the use of organic hosts, and develop other types of perovskite materials.”

Source: “Engineering organic-inorganic perovskite planar heterojunction for efficient carbon dots based light-emitting diodes,” by Haoran Jia, Huanyu Ma, Xiangyang Liu, Donghui Xu, Ting Yuan, Chao Zou, and Zhan’ao Tan, Applied Physics Reviews (2022). The article can be accessed at https://doi.org/10.1063/5.0085692 .