Influence of concentration of different chemical precursors on the physical properties of Cr2O3 thin films elaborated via pneumatic spray

Abstract

In this paper, Cr2O3 thin films were synthesized successfully on glass substrates at 450 °C using a simple and low-cost homemade pneumatic spray system (SP) using two different precursors: chromium chloride and chromium nitrate. A systematic study of the influence of concentration of each precursor used for deposition on the structural, morphological, optical and electrical properties has investigated. The XRD results show that the Cr2O3 films prepared with chromium chloride are polycrystalline with rhombohedral structure and those prepared with low concentration of chromium nitrate have a poor crystallinity. Peaks associated with Cr and O elements are present in EDS analysis that confirm the composition of the films and SEM images revealed a uniform, homogeneous and well covered surface. The measured electrical conductivity was found in the order of 5(Ω.cm)–1. The average transmittance of the films deposited from chromium nitrate is in the range of 60 % and for the films deposited from chromium chloride, it reaches75 % in the visible region. These electrical and optical properties of Cr2O3 thin film ascribed to its wide band gap, are indeed required for optoelectronic devices especially for solar cell window.