Optoelectronic materials utilizing hot excitons or hot carriers: from mechanism to applications

Abstract

Traditionally, hot excitons or hot carriers generated in semiconductors were considered unfavourable for many applications, given that they may cause energy loss and device degradation. However, recently, many new methods have emerged to take advantage of these energetic species to enhance the performance of optoelectronic devices or photochemical reactivity, and consequently the utilization of hot excitons or hot carriers has become a new and promising strategy for the design of new materials. Initially, in this review, we introduce the basic concepts of hot excitons and hot carriers, including the photophysical processes to generate these species and the methods for their characterization. Subsequently, the latest research progress in the development of optoelectronic materials that can utilize either hot excitons or hot carriers is reviewed. The applications of these materials in three major fields are discussed, including photovoltaics, electroluminescence and photocatalysis. Finally, perspectives are given on the promising role of hot excitons and hot carriers in the design of high-performance optoelectronic materials and the challenges faced by researchers in these fields.