Simple low-temperature chemical bath route to synthesize novel Ga-doped ZnO nanostructures for high photoresponse
Ga-doped ZnO (GZO) nanostructures with high photoresponse were deposited on the seed layers of GZO thin films via polyethylene glycol (PEG400)-assisted chemical bath method at low temperatures. GZO thin films were prepared on quartz glass substrates by sol-gel spin coating technique. The structural, optical and photoelectrical properties of the GZO nanostructures were investigated. The scanning electron microscopy images showed GZO nanostructures presented nanosheets at 50 and 60 °C and nanopillars at 70 and 80 °C. X-ray diffraction results revealed that GZO nanostructures had a hexagonal wurtzite structure. Room temperature photoluminescence spectra exhibited ultraviolet emission peak and visible emission peak. The defect emission peak of GZO nanostructures was red-shifted from 521 to 571 nm when the temperature was increased. Moreover, all the samples are photoelectrically active under simulated solar light. High sensitivity and enhanced photocurrent bring a profound understanding to photoswitches and photodetectors using GZO nanostructures.