Effects of annealing time on the structural and optoelectronic properties of p-type conductive transparent Cu–Cr–O films

• Published in: Journal of materials science. Materials in electronics 2016-09, Vol.27 (9), p.9740-9747
• Main Authors: Sun, Chung-Hsing, Tsai, Du-Cheng, Chang, Zue-Chin, Chen, Erh-Chiang, Shieu, Fuh-Sheng
• Format: Article
• Language: English
• Subjects: Annealing; Characterization and Evaluation of Materials; Chemistry and Materials Science; Compressive properties; Electrical resistivity; Materials Science; Opacity; Optical and Electronic Materials; Optoelectronics; Residual stress; Resistivity; Surface roughness
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-016-5037-9

Cu–Cr–O films were prepared by DC magnetron co-sputtering using Cu and Cr targets on fused silica substrates. The as-deposited Cu–Cr–O films were amorphous, semi-transparent, and insulated. After annealing at 800 °C for 30–240 min, the surface roughness and optical transmittances of the resultant films increased, but their electrical resistivity, direct optical band gap (E g ) values, and compressive residual stress decreased. The as-deposited amorphous Cu–Cr–O films crystallized to the delafossite structure of the CuCrO 2 phase and showed p-type conductivity. The maximum optical transmittance of the films was as high as 80 % at a visible wavelength of 740 nm. In addition, the electrical resistivity of the films decreased from 34.72 to 14.73 Ω cm as annealing time increased from 30 to 120 min but became saturated after 240 min. These results indicate that the CuCrO 2 films obtained in this work show promising optoelectronic properties under a suitable annealing time.