Engineering organic–inorganic perovskite planar heterojunction for efficient carbon dots based light-emitting diodes

Abstract

When it comes to building high-efficiency thin-film optoelectronic devices, we are constantly striving to improve the efficiency of charge transport and injection. Device performance is hampered by the low mobility and injection ability of organic charge transporting materials that are routinely used. In this paper, we show that instead of using organics as a hole transporting layer, metal halide perovskite can be used to fabricate high-efficiency carbon dots-based light-emitting diodes for the first time. The organic light-emitting layer and the underlying perovskite layer combine to form an organic–inorganic perovskite planar heterojunction, and the sufficient contact at the junction takes advantage of the high charge mobility of perovskite, facilitating the hole transportation and injection. Moreover, the interaction between perovskite and the organic emitting layer can be engineered via manipulating the halogenic component, thickness, surface morphology, etc., contributing to the device optimization and the understanding of the carrier kinetics in this unique organic–inorganic hybrid optoelectronic device. Our work comprehensively evaluates the full potentials of metal halide perovskite as a hole transporting layer by uncovering the positive effect on hole transportation and injection. As a consequence, our findings open up new avenues for the development of efficient carbon dot-based light-emitting diodes.