Self-Powered Broadband (UV-NIR) Photodetector Based on 3C-SiC/Si Heterojunction

Abstract

Self-powered photodetectors (PDs) are highly desirable for many applications, ranging from smart cities to optical communications. Herein, we report on a self-powered broadband [UV to near-infrared (NIR)] PD based on a single-crystalline SiC (100)/Si (100) heterojunction. In self-powered photovoltaic detection mode, the detector exhibits a high responsivity (2500 V/W at $\text {8.0} \times \text {10}^{\text {-6}}$ W/cm2, 521 nm) and specific detectivity (~1013 Jones at $8.0 \times 10^{-6}$ W/cm2, 521 nm) under UV, visible, and NIR spectral illuminations thanks to the superior rectification property of the heterojunction which results in significantly reducing the dark current. The device also shows high illumination ON/ OFF switching ratios, as high as $\text {2.2} \times \text {10}{^{\text {7}}}$ , with an excellent stability and repeatability. A detailed insight about electron–hole pairs generation, separation, and Fermi-energy level shifting at different illumination conditions has been elucidated via energy band diagrams.