The optoelectronic response of a laterally contacted 2-D MESFET

We describe the photoelectric response of a Two-Dimensional Metal Semiconductor-Field-Effect-Transistor (2-D MESFET) which utilizes laterally contacting gates to the active region. The use of lateral gates allows direct illumination of the conductive channel from the top. Photogains as high as 2.4/spl times/10/sup 7/ have been measured at 0.7 /spl mu/m wavelength and 26 /spl mu/W/cm/sup 2/ optical power intensity. Broad spectral responses from 0.7 /spl mu/m to 1.06 /spl mu/m are also presented. The new feature of this device is a spectral response which can be tuned by the applied gate bias and also a higher responsivity which is related to the top illumination unimpeded by the top gate.