A review of the properties, synthesis and applications of lanthanum copper oxychalcogenides

The study of layered materials has been a significant and fascinating area due to their unique physical and chemical properties. Among various layered materials, lanthanum copper oxychalcogenides [LaCuOX (X = S, Se, Te)] have drawn a lot of attention from researchers. The study of LaCuOX was initially focused on optoelectronic performance due to their excellent optical and electronic properties. Recently, it was found that the layered LaCuOX materials also exhibit good thermoelectric (TE) properties, providing an opportunity to achieve high energy conversion efficiency through the TE effects. In this report, an overview of recent advances in LaCuOX research is provided, including crystal and electronic structure, synthetic methods, physical properties and practical applications as well as some strategies to optimize their transport properties. Theoretical and experimental results on LaCuOX crystals or thin films are both discussed. Finally, the challenges and outlook for LaCuOX are evaluated based on current progress.