Highly Sensitive Photoelectric Detection and Imaging Enhanced by the Pyro‐Phototronic Effect Based on a Photoinduced Dynamic Schottky Effect in 4H‐SiC

• Published in: Advanced materials (Weinheim) 2022-09, Vol.34 (35), p.e2204363-n/a
• Main Authors: Zhang, Yueming, Wang, Yi‐Chi, Wang, Longfei, Zhu, Laipan, Wang, Zhong Lin
• Format: Article
• Language: English
• Subjects: Commercialization; Contact resistance; Electric contacts; Illumination; Materials science; Optoelectronic devices; Photoelectricity; photoinduced dynamic Schottky effect; pyro‐phototronic effect; Response time; self‐powered devices; Semiconductor materials; sensors; SiC; Silicon carbide; Single crystals; Ultraviolet detectors; Work functions
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202204363

Silicon carbide (SiC), one of the third‐generation semiconductor materials with excellent electrical and optoelectronic properties, is ideal for high light‐sensing performance. Here, a self‐powered SiC ultraviolet (UV) photodetector (PD) is constructed with wider applicability and higher commercialization potential. The great performance of the PD is realized by a remarkable photoinduced dynamic Schottky effect derived from the symbiotic modulation of Schottky and Ohmic contact. Using the pyro‐phototronic effect that exists in the N‐doped 4H‐SiC single crystal PDs, a fast pyroelectric response time of 0.27 s is achieved, which is almost ten times shorter than that obtained from the steady‐state signal under UV illumination. The maximal transient photoresponsivity reaches 9.12 nA mW−1, which is ≈20% higher than the conventional photoelectric signal. Moreover, different regions of the 4H‐SiC centimeter‐scale chip output distinct signals under UV illumination, demonstrating efficient optical imaging and information transmission capabilities of this device. This work not only reveals the fundamental optoelectronic physics lying in this vital third‐generation semiconductor, but also sheds light on its potential photosensing applications for large‐scale commercialization. A high‐performance self‐powered 4H‐SiC ultraviolet photodetector is realized using a strong photoinduced dynamic Schottky effect, and the pyro‐phototronic effect is first revealed in N‐doped 4H‐SiC, which is beneficial to further enhance the photodetection performance. Moreover, via delicate position designs of electrodes, the 4H‐SiC chip reveals efficient optical imaging and information transmission capabilities.