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

Abstract

The n-Zn/p-Si heterostructure detector for ultra-violet was fabricated by pulsed laser deposition. Plasma oxygen was used for the deposition of n-ZnO thin films to decrease the concentration of deep-level defects such as oxygen vacancies and zinc interstitials. The electron concentration of n-ZnO thin film was reduced to a low level of 10 14 cm −3, resulting in the depletion width in p-Si decreasing significantly. The spectral response of the detector shows that the responsivity to visible light has been eliminated effectively by using plasma oxygen in the ZnO film growth. The visible–blind mechanism for the n-Zn/p-Si heterostructure detector has been discussed.