Quantitatively Exploring the Effect of a Triangular Electrode on Performance Enhancement in a 4H-SiC Metal-Semiconductor-Metal Ultraviolet Photodetector

A model of novel triangular electrode metal-semiconductor-metal (TEMSM) and conventional electrode metal-semiconductor-metal (CEMSM) detectors is established by utilizing the ISE-TCAD simulator. By comparing the simulated results of TEMSM and CEMSM with experimental data, the model validity is verified and the TEMSM detector shows a superiority of a 113% photocurrent increase of 25.4 nA and similar low dark current of 3.16 pA at 30 V bias over the CEMSM device. Furthermore, the electrode angle α, width W and spacing S are optimized to obtain the enhanced device features including high UV−to-visible rejection ratio and large responsivity, etc. Under 30 V bias, the maximum UV-to-visible rejection ratio, comparable responsivity and external quantum efficiency at 310 nm are 13049, 0.1712 A/W and 68.48% for a TEMSM detector with device parameters of α=60°, W=3 μm and S=4 μm, respectively.