Multifunctional Optoelectronic Device Based on an Asymmetric Active Layer Structure

A single device with a variety of capabilities is highly attractive for the increasing demands of complex and multifunctional optoelectronics. A hybrid heterojunction formed between CsPbBr3 halide perovskite and chalcogenide quantum dots is demonstrated. The heterojunction served as an asymmetric active layer allows not only charge separation/exciton dissociation in a benign process, but also carrier injection/recombination with the suppression of bulk and interfacial nonradiative recombination. An individual device incorporating such a heterojunction is therefore implemented with an integration of proof-of-concept functions, including a voltage controllable multicolor light-emitting diode, an exceptionally high photovoltage energy-harvesting device, and an ultrafast photosensitive detector. The figures of merit of the light-emitting diode remarkably surpass those of the corresponding singleactive-layer device, particularly in terms of its bright electroluminescence and superior long-term stability. The asymmetric active layer concept provides a feasible route to design efficient multifunctional and monofunctional devices in the future.