Photo-Illuminated InP Terahertz IMPATT Device

The dynamic properties of indium phosphide (InP) double drift IMPATT diode operating at 0.3 THz region are studied through a simulation experiment. The study indicates that InP IMPATT is capable of generating high RF power (41.7 mW) at 0.3 terahertz with 10% efficiency. However, the parasitic series resistance is found to produce a 3.0% reduction in the negative conductance and the RF power of the diode. The effect of photo-illumination on the device is also investigated by studying the role of enhanced saturation current on the THz frequency performance of this IMPATT device. A modified double iterative simulation technique developed by the authors is used for this purpose. It is found that (i) the negative conductance and (ii) the negative resistance of the device decrease, while, the frequency of operation and the device quality factor shift upward with increasing saturation current. The upward shift in operating frequency is found to be more (30 GHz) when the device performance is controlled by the hole saturation current rather than by the electron dominated saturation current. The magnitudes of electron and hole ionization rates in the semiconductor have been found to be correlated with the above effect. These results thus indicate that InP DDR IMPATT diode is highly photo-sensitive even at THz range of frequencies.