Gate-tunable optoelectronic properties of a nano-layered GaSe photodetector

Recently, two-dimensional materials were widely studied as candidates for new generation of photodetectors. In this paper, we reported on the fabrication and the optoelectronic characterizations of p-type gallium selenide (GaSe) back-gated field effect transistor based photodetector. The phototransistor showed excellent gate control capability with an I sub(ON)/I sub(OFF) value exceeding 10 super(3). The photoresponsivity can be easily tunable to maximum value of 1.4 AW super(-1) by changing the gate voltage, however, the photodetector showed the best performance at gate voltage of ?18V, with photoresponsivity, external quantum efficiency and detectivity of 0.9 AW super(-1), 210% and 8.08 x 10 super(11) cmHz super(0.5) W super(-1), respectively.