GATED PHOTODETECTOR BASED ON GAN ALGAN HETEROSTRUCTURE FIELD-EFFECT TRANSISTOR/

The authors report a 0.2 mu m gate GaN/AlGaN heterostructure field eff ect transistor which operates as a visible blind photodetector with re sponsivities as high as 3000 A/W for wavelengths from 200 to 365 nm. T he responsivity falls by three orders of magnitude for wavelengths gre ater than 365nm. Using a CW He-Cd laser (wavelength 325 nm), we measur ed a response time of order 0.2ms. A model explaining the detector ope ration is in good agreement with the experimental data.