High—Performance Solar‐Blind Deep Ultraviolet Photodetector Based on Individual Single‐Crystalline Zn₂GeO₄ Nanowire

Abstract

Solar‐blind deep ultraviolet (DUV) photodetectors have been a hot topic in recent years because of their wide commercial and military applications. A wide bandgap (4.68 eV) of ternary oxide Zn 2 GeO 4 makes it an ideal material for the solar‐blind DUV detection. Unfortunately, the sensing performance of previously reported photodetectors based on Zn 2 GeO 4 nanowires has been unsatisfactory for practical applications, because they suffer from long response and decay times, low responsivity, and quantum efficiency. Here, high‐performance solar‐blind DUV photodetectors are developed based on individual single‐crystalline Zn 2 GeO 4 nanowires. The transport mechanism is discussed in the frame of the small polaron theory. In situ electrical characterization of individual Zn 2 GeO 4 nanowires reveals a high gain under high energy electron beam. The devices demonstrate outstanding solar‐blind light sensing performances: a responsivity of 5.11 × 10 3 A W −1 , external quantum efficiency of 2.45 × 10 6 %, detectivity of ≈2.91 × 10 11 Jones, τ rise ≈ 10 ms, and τ decay ≈ 13 ms, which are superior to all reported Zn 2 GeO 4 and other ternary oxide nanowire photodetectors. These results render the Zn 2 GeO 4 nanowires particularly valuable for optoelectronic devices.