Optoelectronic Properties of Single-Crystalline Zn₂GeO₄ Nanowires

In this work, Zn₂GeO₄ nanowires (NWs) were successfully synthesized on Si(100) substrates through carbon thermal reduction and a vapor–liquid–solid method. The NWs were of around 100 nm diameter and high aspect ratio (AR > 150). High-resolution transmission electron microscopy studies indicate that the NWs are single-crystalline with [110] growth direction. Moreover, the atomic resolution high-angle annular dark-field and bright-field images of scanning transmission electron microscopy have distinguished the different elements. They also further identified the structure of Zn₂GeO₄ and located the positions of the elements. Additionally, we have fabricated devices and measured the electrical properties of a single NW. It is remarkable that individual Zn₂GeO₄ NW devices exhibited excellent optoelectronic properties with fast switching speed under 254 nm UV illuminations. Furthermore, with short wavelength UV illumination, as we soaked Zn₂GeO₄ NWs in methyl orange solution, the methyl orange was degraded. Therefore, Zn₂GeO₄ NWs have potential applications in UV photodetectors and degradation of organic pollutants.