Solution-assembled nanowires for high performance flexible and transparent solar-blind photodetectors

Solar-blind photodetectors based on Zn₂GeO₄ (ZGO) nanowires (NWs) with high transparency and good flexibility were successfully fabricated on a polyethylene terephthalate (PET) substrate using a facile all solution-processible method. The electrodes and functional channels are constructed with silver NWs (Ag NWs) and ZGO NWs, respectively, using a spray coating method. The spray-coated all-NW device exhibited high transparency, good mechanical bending stability, high photoresponse, and short cutoff wavelength. The Schottky barrier between the Ag-ZGO NWs together with the junction barrier between interconnecting ZGO NWs contributed to a high photoresponse and improved switching time in the devices. We propose that the unique energy band structure of the ZGO NW networks provides an additional mechanism to further reduce the cutoff wavelength in solar-blind photodetectors.