Low-Dimensional In2Se3 Compounds: From Material Preparations to Device Applications

Nanostructured In2Se3 compounds have been widely used in electronics, optoelectronics, and thermoelectrics. Recently, the revelation of ferroelectricity in low-dimensional (low-D) In2Se3 has caused a new upsurge of scientific interest in nanostructured In2Se3 and advanced functional devices. The ferroelectric, thermoelectric, and optoelectronic properties of In2Se3 are highly correlated with the crystal structure. In this review, we summarize the crystal structures and electronic band structures of the widely interested members of the In2Se3 compound family. Recent achievements in the preparation of low-D In2Se3 with controlled phases are discussed in detail. General principles for obtaining pure-phased In2Se3 nanostructures are described. The excellent ferroelectric, optoelectronic, and thermoelectric properties having been demonstrated using nanostructured and heterostructured In2Se3 with different phases are also summarized. Progress and challenges on the applications of In2Se3 nanostructures in nonvolatile memories, photodetectors, gas sensors, strain sensors, and photovoltaics are discussed in detail. In the last part of this review, perspectives on the challenges and opportunities in the preparation and applications of In2Se3 materials are presented.