Recent Advances in SnSe Nanostructures beyond Thermoelectricity

Layered SnSe is an emerging class of black phosphorus, which is non-toxic, eco-friendly, and chemically stable. Recently, SnSe nanostructures have triggered more research interest and enabled broad applications beyond demonstrating their great performances on thermoelectricity. However, there are also a great many significant studies of SnSe nanostructures beyond thermoelectricity. SnSe quantum dots, nanosheets, nanowires, and thin films with diverse morphologies have been synthesized using various chemical and physical preparation approaches. SnSe is a multi-phase semiconductor, and its nanostructures endow unique properties, including small electron effective mass, ultralow thermal conductivity, huge anisotropy, and the largest 2D piezoelectric coefficient ever predicted. The versatility of SnSe nanostructures can enable potential applications ranging from ultrafast photonics, logic devices, photodetectors, solar cells, photocatalysis, energy storage, and biology to more cutting-edge interdisciplinary subjects. In this review, the recent advances made in SnSe nanostructures are summarized, covering basics, synthesis, properties, and applications, just giving a passing comment on thermoelectricity. An in-depth perspective on the challenges and prospects of SnSe nanostructures toward broad and practical applications is also given.