Photosensitive n-In2O3 / p-InSe Heterojunctions with Nanostructured Surface of the Frontal Layer

We report on photosensitive n-In2O3 / p-InSe heterojunctions with nanostructured In2O3 frontal layer. It was established that photoresponse spectra of the heterojunctions significantly depend on the surface topology of the oxide. this means that the oxide with semiconductor substrate is not only an active component of the structure, but also serves as a cell diffraction material. Surface topology of the oxide was studied by means of the atomic force microscope. At various conditions of oxidation of InSe the surface of the samples contained nanoformations preferably in the form of nanoneedles. Their location has both a disordered and ordered character. A dimensional optical effect in the oxide was revealed 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 the generation of carriers in the semiconductor is. These changes consist in the energy broadening of the heterojunction photoresponse spectrum as well as in the 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 intensive excitonic peak in the spectrum takes place.