Theoretical modeling and design aspects of cubic-phase GaN homojunction-based UVC light sensor

Abstract

We designed a cubic-phase gallium nitride (c-GaN) homojunction for ultraviolet-C (UVC) detection. A physical model approach was employed to design the dimensions of the detector and the doping concentrations of each layer. The calculated electrical and optoelectronic properties were employed to perform a simulation program with integrated circuit emphasis (SPICE) equivalent circuit model to integrate c-GaN photodetection capabilities into a CAD electronic simulator. The model allows estimating the transport properties in the darkness and under ultraviolet (UV) illumination conditions. Furthermore, the effect of depletion capacitance was taken into account thinking in the circuitry amplification stage. When a transient UVC flash occurs, the SPICE simulation revealed that the output signal is in the order of 300 μV, which is suitable to be amplified by a transimpedance amplifier.