Modeling Electron Behavior in the B-Si Photodetector

Photodiodes based on the Boron on Silicon junction (B-Si) show excellent responsivity to DUV and VUV photons, radiation hardness, and impressive electrical characteristics.However, the currently used models describing the working principles do not sufficiently predict the junction's properties.We review three models: the ultra-shallow 𝛿-doping model, the charge transfer model, and the Schottky-Mott model.We recognize that the 𝛿-doping model requires very high dopant concentrations, not attained at lower deposition temperatures (400°C).We note that in the charge transfer model that electron movement from the Si to the B layer creates a potential barrier, explaining the rectifying properties.Finally, we find that the B-Si heterojunction fits the Schottky-Mott model, which is unusual as a-B is not considered a metal.