Amorphous indium-gallium-zinc-oxide (α-IGZO) composed of In₂O₃,Ga₂O_3and ZnO is an n-type semiconductor with a band width of 3.5eV,and currently it has become a hot rese arch field of field-effect transistors for its properties.In order to investigate its potential application for fu ture photoelectric sensors,by fabricating electrodes with a mask,here we present a bottom-gate/top-contact field-effec t transistor with structure of ITO/SiO₂(400nm)/α-IGZO(50nm)/Αl in which α-IGZO acts as active layer,and its photosensitive properties are characterized.After thermally evaporating Al layer to fabricate drain and sourc e electrodes with a mask,the device is annealed in ambient air at 350℃ for an hour,and the α-IGZO-based thin-f ilm field-effect transistor (TFT) shows good transistor characteristics of a mobility of 0.57cm²/Vs at VG S=30V and a threshold voltage of 15.0V.Under white light illumination with an intensity of 8.1mW/cm²,the device shows obviously enha nced photosensitive properties,its mobility increases to 1.34cm²/Vs at VDS=20V and VGS=30V,its threshold voltage reduces t o －15.0V,and its current ratio (K) of photocurrent to current in dark reaches a maximum at VGS=2.5V with a responsivity of 1.11Α/W presentin g good time-responsive characteristics.