Document Type : Research Paper

Authors

• Zahra Sadat Hosseini ¹
• Abdollah Mortezaali ²

¹ Photonics and Quantum Technologies Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran.

² Department of Condensed Matter Physics, Faculty of Physics, Alzahra University, Tehran, Iran.

Abstract

In this research, ultra violet (UV) photodetectors based on rather aligned ZnO nanorods thin film with controllable responsivity were fabricated. Aligned nanorods were grown on the seeded glass substrates by chemical bath method. Then, they were characterized using Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), photoluminescence (PL), and Energy Dispersive X-ray Analysis (EDAX). The effect of perimeter and area variation of interdigitated electrodes on the responsivity of UV ZnO nanorods-based photodetector was investigated. The responsivity shows a decreasing trend with decreasing electrode perimeter and keeping the area constant. By keeping the perimeter constant in the maximum value, it is observed that the response of the photodetector is increased with increasing the gap between the fingers of the electrode so that the gap of 160 µm reaches the maximum as high as 105 AW-1 at 2 V bias voltage. The dominant mechanism for change of the responsivity with electrode geometry is purposed on the basis of variation in the area of depletion regions resulting from Schottky barriers between ZnO and Au and the formed barriers between ZnO nanorods due to adsorption and desorption of oxygen species. This research demonstrates a simple way of optimizing the responsivity of photodetector devices for practical applications.

Keywords

• UV photodetector
• electrode geometry
• aligned nanorods
• Zinc Oxide
• interdigitated comb-like electrodes

Main Subjects

• INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY