Study and Simulation of MSM Photodetector Based on the AlxGa1-xN/GaN Structure

In this paper, we present the structure of an MSM Al0.25Ga0.75N/GaN photodetector operating in ultraviolet. The structure studied is made from the alloy of two binary semiconductor materials GaN and AlN. Modeling and simulation were carried out by Atlas-Silvaco software. The component characteristics dark current, photocurrent and reactivity were simulated and optimized. The optimal structure corresponds to the aluminum concentration of 25%. A dark current around 3.47 nA under 1 V bias was obtained. Then we changed the polarization to 10 V the dark current achieved is equal to 0.24 µA. Also, the transmission and reflection coefficients were studied. The optimal responsivity reaches 0.28 A/W at a wavelength λ = 250 nm and a polarisation of 10 V.