Effect of substrate illumination on the characteristics of an ion implanted GaAsOPFET

An analytical model of an ion-implanted GaAs MESFET has been developed cons idering the illumination from the substrate. The ion-implanted profile of t he channel region is represented by Pearson IV distribution. Modulation of the channel opening due to the internal photovoltage has been considered. T he I-V characteristics, the photocurrent, the internal photovoltage and the transconductance of the device have been calculated and discussed. The sub strate doping concentration is found to affect the overall drain-source cur rent under illumination, which indicates a significant substrate affect on the device characteristics, The illumination also enhances the dram current of the MESFET compared to that in the dark. The I-V characteristics, trans fer characteristics and the ratio of drain currents under illumination and in the dark have been plotted and discussed.