Performance Investigation of 4H-SiC PIN Photodiodes with Dual-Emitter Designs for Enhanced UV-C Detection

We present a comprehensive analysis of various dual emitter (DuE) designs for 4H-SiC PIN photodiodes, which incorporate heavily doped p regions within a shallow p- emitter. The p regions act as low-resistance pathways, facilitating efficient transport of photogenerated carriers to the ohmic contacts. Moreover, the lateral electric field established at the p/p junction promotes effective separation of charge carriers generated proximate to the surface. By systematically varying the p path widths and spacings, we analyze the impact of different design geometries on the photodiode sensitivities and investigate the carrier collection mechanisms. Sensitivity response measurements at 210 and 280 nm demonstrate that DuE designs significantly enhance UV-C sensitivity while maintaining high responsivity in the UV-A and UV-B ranges. The best performing design investigated achieves a median sensitivity of 33.4 mA/W at 210 nm, representing a substantial improvement over reference designs.