Nano Research

Article Title

Ultrahigh quantum efficiency photodetector and ultrafast reversible surface wettability transition of square In2O3 nanowires


square In2O3 nanowires, crystal facet, photodetector, reversible wettability transition


ABSTRACT Due to a large surface-to-volume ratio, the optoelectronic performance of lowdimensional semiconductor nanostructure-based photodetectors depends in principle on chemisorption/photodesorption at the exposed surface, but practical examples that show such an effect are still unavailable. Some theoretical calculations have predicted that the {001} facets of In2O3 can effectively accumulate photogenerated holes under irradiation, providing a model material to examine whether the facet cutting of nanowires (NWs) can boost their optoelectronic performance. Herein, we present the design and construction of a novel nanowire-based photodetector using square In2O3 NWs with four exposed {001} crystal facets. The photodetector delivers excellent optoelectronic performance with excellent repeatability, fast response speed, high spectral responsivity (Rλ), and high external quantum efficiency (EQE). The Rλ and EQE values are as high as 4.8 × 106 A/W and 1.46 × 109%, respectively, which are larger than those of other popular semiconductor photodetectors. In addition, the square In2O3 NWs show hydrophobic wettability as manifested by a contact angle of 118° and a fast photoinduced reversible switching behavior is observed.

Graphical Abstract


Tsinghua University Press