International Journal of Photoenergy (Jan 2015)

Hydrothermal Growth of Quasi-Monocrystal ZnO Thin Films and Their Application in Ultraviolet Photodetectors

  • Yung-Chun Tu,
  • Shui-Jinn Wang,
  • Tseng-Hsing Lin,
  • Chien-Hsiung Hung,
  • Tsung-Che Tsai,
  • Ru-Wen Wu,
  • Kai-Ming Uang,
  • Tron-Min Chen

DOI
https://doi.org/10.1155/2015/261372
Journal volume & issue
Vol. 2015

Abstract

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Quasi-monocrystal ZnO film grown using the hydrothermal growth method is used for the fabrication of Cu2O/ZnO heterojunction (HJ) ultraviolet photodetectors (UV-PDs). The HJ was formed via the sputtering deposition of p-type Cu2O onto hydrothermally grown ZnO film (HTG-ZnO-film). The effect of annealing temperature in the nitrogen ambient on the photoluminescence spectra of the synthesized ZnO film was studied. The optoelectronic properties of Cu2O/ZnO film with various Cu2O thicknesses (250–750 nm) under UV light (365 nm; intensity: 3 mW/cm2) were determined. The UV sensitivity of the HTG-ZnO-film-based UV-PDs and the sputtered ZnO-film-based UV-PDs were 55.6-fold (SHTG) and 8.8-fold (Ssputter), respectively. The significant gain in sensitivity (SHTG/Ssputter = 630%) of the proposed ZnO-film-based device compared to that for the device based on sputtered film can be attributed to the improved photoelectric properties of quasi-monocrystal ZnO film.