▎ 摘 要
Novel graphene-oxide-semiconductor (GOS) nanowire phototransistors have been fabricated for the first time. Mono layer graphene, high-K HfO2, and CdSe nanowire (NW) were used as transparent topgate, gate dielectric, and conductive channel, respectively. Electric measurements of the devices reveal a clear field effect In the dark, the on/off ratio, threshold voltage, subthreshold swing, and peak transconductance are about 4.9 x 10(6), -1.5 V, 120 mV dec(-1), and 2.3 mu S, respectively. The photo-response characterization demonstrates that the gate voltage has a remarkable modulation effect on the responsivity of the phototransistors. Under 633 nm tight illumination, the responsivity, gain, and specific detectivity can be as high as 1.06 x 10(7) A W-1, 1.93 x 10(7), and 9.68 x 10(15) Jones, respectively. To the best of our knowledge, these values are among the highest reported so far for NW-based photodetectors. Our results demonstrate that GOS NW phototransistors promise a potential application in weak light detecting, which is highly desired in future optical communication or nanoscale integrated optical circuits.