Semi-insulating 4H-SiC based PIN photodiodes for X-ray detection

Silicon carbide is a wide-bandgap semiconductor with excellent thermal stability, high breakdown field, and strong radiation resistance, making it highly suitable for optoelectronic applications. However, challenges in growing thick intrinsic layers and p-type doping limit the performance of SiC-based photodetectors. In this work, a PIN-type photodetector based on semi-insulating 4H-SiC was fabricated. The p-type and n-type layers were replaced with organic semiconductors to avoid epitaxial growth and doping. The prototypical devices exhibited promising X-ray detection performance, achieving an X-ray sensitivity of 7019.35 μC × Gy⁻¹ cm⁻², and also demonstrated strong ultraviolet (UV) detection capability in the 350–380 nm range. Furthermore, the device exhibited excellent long-term stability, maintaining a high on/off ratio even after 384 hours. This study provides new insights for developing high-performance, low-noise, and stable SiC-based photodetectors.