Broadband 4H-SiC Hot Electron Photodetector Enhanced by TiN Hemispherical Nanocavities

Photodetectors (PDs) based on 4H silicon carbide (4H-SiC) have excellent advantages in intense radiation, high temperature, or corrosion application scenarios. However, the wide bandgap of 4H-SiC restricts its applications to the ultraviolet (UV) range below 400 nm. Here, we apply a novel plasmonic titanium nitride (TiN) electrode into 4H-SiC PD, extending the photocurrent response to a telecommunications wavelength of 1310 nm through the hot-electron effect. Especially, the photocurrent of the proposed 4H-SiC PD, under 660 nm illumination and 20 V bias, is enhanced by four orders of magnitude higher than the control, yielding a 325-fold increase in external quantum efficiency (EQE) andR, and aD*of 1.44 × 1011Jones with an increase of three orders of magnitude. More, the photocurrent enhancement ratio of the plasmonic PD relative to the control also reaches 415, 81, and 50 at wavelengths of 850, 980, and 1310 nm, respectively, enabling the proposed 4H-SiC PD to achieve broadband response enhancement. This underscores the effectiveness of the plasmonic TiN electrode in augmenting response in 4H-SiC PDs via the plasmonic resonant effect. This advancement in 4H-SiC PDs paves the way for next-generation, cost-effective PD technologies.