TIME-DEPENDENT ANALYSIS OF AN ION-IMPLANTED GAAS OPFET

A time-dependent analysis of the electrical characteristics of an ion implanted GaAs optical field effect transistor (OPFET) has been carrie d out. Both the cases of light turning on and off at a reference time t = 0 have been considered. The photovoltaic effect across the Schottk y junction and the depletion width modulation in the active layer have been taken into account. The threshold voltage, channel charge, chann el conductance, drain-source current, transconductance, and gate-sourc e capacitance of the device under light turning on and off conditions have been evaluated. When light is turned on, all the parameters incre ase with time before reaching the steady-state value and when light is turned off, these parameters decrease with time and reach their respe ctive values corresponding to dark condition. The time under on condit ion is less than that under off condition.