Photosensitive CuFeO2/n-InSe Heterojunctions

Abstract

Photosensitive anisotypic CuFeO2/n-InSe heterojunctions were fabricated by the method of lowtemperature spray pyrolysis. An aqueous solution of copper dichloride CuCl2•2H2O and iron trichloride FeCl3•6H2O was sprayed onto the InSe substrate heated to 623 K. As a result, p-type CuFeO2 films with a thickness of ~ 0.3 m and a band gap of 2.6 eV were obtained. Contacts were formed using silver-based conductive paste. The I-V characteristics were studied at temperatures from 295 to 336 K. It was shown that the temperature dependence of the height of the potential barrier is linear. Based on the analysis of the temperature dependences of forward and reverse I-V characteristics, the dynamics of change of energy parameters was established and the role of energy states at the boundary of the heterojunction in the formation of the contact potential difference was clarified. The approximation of I-V characteristics was carried out within the framework of the model, which takes into account the influence of series and shunt resistances. The values of the diode coefficient, series and shunt resistances of the heterojunction were found. The mechanisms of formation of direct and reverse currents through the CuFeO2/n-InSe energy barrier were determined. The spectral dependence of the quantum efficiency of heterojunctions in the range of photon energies from 1.2 to 3.2 eV was studied. The effect of light absorption in heterostructure materials on its general photosensitivity was analyzed. The obtained results confirmed the promise of CuFeO2/n-InSe heterojunctions for photoelectronics.

Fe2O3/p-InSe Heterostructures Produced by Spray Pyrolysis Method

“…In turn, an equally important role in the creation of a high-quality heterojunction is played by the thin film of the frontal layer, which must form a defect-free interface when in contact with the substrate. It is the optimal choice of chemical components and the film sputtering technique that allow creating heterostructures with the necessary electrical and photovoltaic parameters [7,8]. In this work, the choice was made on Fe2O3 films.…”