Effects of SiO_2 Passivation Layer on Performances of i-GaN Schottky Photodetectors

The lateral-geometry Schottky photodetectors have been fabricated on the unintentionally doped i-GaN grown by MOCVD.A SiO_2 passivation layer has been grown on the zone between the ohmic contact and the rectifying contact by the magnetron sputtering.The performances of Schottky photodetectors have been characterized.Through comparison between the performances of Schottky photodetectors with and without SiO_2 passivation layer,the results show the reverse leakage current of the photodetectors with SiO_2 passivation layer is greatly reduced,and its forward turn-on voltages are not affected,and the spectral responsivity of the photodetectors is obviously improved at light wavelength between 300 and 365nm.These may be attributed to SiO_2 passivation layer which reduces the surface defects of electrodes spacing zone for the Schottky photodetectors.