Visible-blind ultra-violet detector based on n-ZnO/p-Si heterojunction fabricated by plasma-assisted pulsed laser deposition

The n-Zn/p-Si heterostructure detector for ultra-violet was fabricated by pulsed laser deposition. Plasma oxygen was used for the deposition n-ZnO thin films to decrease the concentration of deep-level defects such as oxygen vacancies and zinc interstitials. The electron concentration n-ZnO thin film was reduced to a low level of 1014 cm(-3), resulting in the depletion width in p-Si decreasing significantly. The spectral of the detector shows that the responsivity to visible light has been eliminated effectively by using plasma oxygen in the ZnO film growth. visible-blind mechanism for the n-Zn/p-Si heterostructure detector has been discussed. (C) 2007 Elsevier Ltd. All rights reserved.