Synthèse et caractérisations d'oxyde semiconducteurs de type p en couches minces par chimie douce pour des applications photovoltaiques

Abstract

Chromium oxide (Cr2O3) thin films have been deposited by the pneumatic spray method on glass substrates to obtain good optoelectric properties for use in photovoltaics. We studied the effect of the molar concentration of chromium chloride and chromium nitrate, substrate temperature, indium doping and copper doping on the structural, morphological, optical, and electrical properties (by various techniques XRD, SEM, EDS, UV-Visible, and the four probe technique) to improve the quality of Cr2O3 thin films. X-ray diffraction (XRD) study shows that the chromium chloride crystallization is better than that of nitrate, with a (110) preferred orientation in rhombohedral structure. SEM images revealed that the films were well adherent, uniform, pore and crack – free. The optimal temperature of the substrate is 500 °C, the average transmittance of the films is in the range of 60% (Eg varies from 3.46 to 3.58 eV), and the electrical conductivity is 16.61(Ω.cm)-1. The In and Cu doped chromium oxide films with percentages of dopant (0, 2, 4, 6, and 8 wt.%) were examined. The films doped with indium revealed improvements in their optical and electrical properties. Contrary to films doped with Cu. The highest transmittance value of 94% and a better conductivity value of 79 (Ω.cm)-1 with the greatest figure of merit value 1.2× 10−3 (Ω-1) are obtained for the 4 wt.% In doped Cr2O3 films, making it a convenient p-type transparent conducting oxide for use in many optoelectronic devices and solar cell applications.