Physical Modeling and Design of a Nonvolatile Optically Gated High‐Power Diamond Transistor

In this work, we present the theory of an optically gated diamond-based junction field-effect transistor implemented on a type Ib diamond substrate with deep nitrogen donor-like traps and a boron-doped epi-layer on top. Using sub-gap lasers with intensities as low as 10 W/cm 2 , electrons are optically excited from the nitrogen traps to the conduction band of the diamond substrate, thus enabling the back gate to exercise an efficient control on modulating the space-charge region at the junction and therefore the channel conductivity. We show that the device can deliver a current of 7 µA/µm, or equivalently 1750 A/cm 2 , while switching at a frequency greater than 2 kHz, in a form factor of 5 µm 2. The breakdown voltage is found to be greater than 1850 V, with a breakdown field strength of ∼11 MV/cm. Moreover, the device supports non-volatile operation for higher immunity to electromagnetic interference. Early experimental results conducted in an unoptimized device structure are in excellent agreement with the model, while more advanced experimental studies, driven by the predictive model, are currently underway.