Optoelectronic characteristics of UV photodetectors based on sol–gel synthesized GZO semiconductor thin films

• Published in: Journal of alloys and compounds Vol. 596; pp. 145 - 150
• Main Authors: Tsay, Chien-Yie, Yu, Shih-Hsun
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.05.2014; Elsevier
• Subjects: Aluminum; Applied sciences; Co-doping; Detectors; Electronics; Exact sciences and technology; Ga-doped ZnO; Gallium base alloys; Illumination; Optoelectronic devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; So-gel method; Sol gel process; Thin films; Transparent oxide semiconductor; UV photodetector; Zinc oxide; Transparent oxide semiconductor; So-gel method; UV photodetector; Ga-doped ZnO; Co-doping; Transparency; Semiconductor materials; Voltage current curve; Impurity density; Aluminium addition; Photodetector; Thin film; Ultraviolet detector; Sol gel process; Illumination; Zinc oxide; Photoconductivity; Gallium addition; Codoping
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2014.01.066

[Display omitted] •Transparent GZO, GZO:B, GZO:Al semiconductor films were prepared by sol–gel method.•The GZO:Al films had the lowest resistivity and the highest Hall mobility.•All ZnO-based UV photodetectors operated in the photoconductive mode.•The GZO:Al detector had the highest responsivity of 3.22A/W at a bias of 5V. Ga-doped ZnO (GZO), B–Ga codoped ZnO (GZO:B), and Al–Ga codoped ZnO (GZO:Al) transparent semiconductor thin films and photoconductive ultraviolet (UV) detectors were fabricated on alkali-free glass substrates by the sol–gel route. The doping concentration of Ga was 0.5at.%, and that of Ga plus B or Al was 1at.% in the precursor solutions. The structural, electrical, and optical properties of GZO, GZO:B and GZO:Al thin films were compared and the photoconductivity and photoresponsivity of ZnO-based UV photodetectors are reported. All as-prepared ZnO-based thin films had high transparency in the visible region, and the GZO:Al thin film exhibited the best electrical properties. Current–voltage (I–V) characteristics in dark and illuminated conditions showed that the resistance of the films fell by more than an order of magnitude upon UV light illumination. In this study, we found that the photoconductive UV detector based on GZO:Al film exhibited the highest responsivity, 3.22A/W at 5V bias under UV light illumination.