All-inorganic non-perovskite copper halides for light emission

Achieving commercially viable luminescent devices requires the design of synthetic materials that are non-toxic, stable, and cost effective. However, despite the tremendous efforts to optimize the synthesis and improve the functionality of conventional semi-conductors, the commercial potential and performance of these ma-terials are often compromised. All-inorganic copper halides, which are characterized by an anionic CumXn framework counterbalanced by inorganic cations, have emerged as potential candidates for next -generation light-emitting devices. Their structural versatility com-bined with their superior emission performance make them attrac-tive for the development of semiconductor devices realized at low cost. Here, we discuss the current understanding of the structural and photophysical properties of copper halides and present recent advances in their integration into devices and critical issues for real-izing next-generation semiconductor devices for optoelectronics.