Photoelectric properties of In₂O₃-InSe heterostructure with nanostructured oxide

Abstract

The photosensitive In₂O₃-p-InSe heterostructures, in which the In₂O₃ frontal layer has a nanostructured surface, have been investigated. The photoresponse spectra of these heterostructures have been found as essentially dependent on surface topology of oxide. The obtained results indicate that In₂O₃ oxide is not only an active component of the structure but also acts as a diffraction cell element. Oxide surface topology was investigated using the atomic-force microscope technique. Under different conditions of InSe oxidation, the sample surfaces contained nanoformations preferably in the form of nano-islands. Their location acquired both disordered and ordered characters. A dimensional optical effect in the oxide layer was found to be due to the anisotropic light absorption in InSe. The higher deviation of incident light from its normal direction due to a nanostructured surface is, the higher variation in generation of carriers in this semiconductor is. These changes consist in the energy broadening of the heterostructure photoresponse spectrum as well as in peculiarities of the excitonic line. The higher density and ordering of the nanoneedles on the oxide surface is, the higher long-wave shift and more intense excitonic peak in spectrum takes place.