A broadband, self-powered, and polarization-sensitive PdSe₂ photodetector based on asymmetric van der Waals contacts

• Main Authors: Zhang, Xuran, Dai, Mingjin, Deng, Wenjie, Zhang, Yongzhe, Wang, Qi Jie
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics; Asymmetric Schottky Barriers; PdSe2; Polarization Sensitive; Self-Powered; van der Waals Contacts
• Online Access: https://hdl.handle.net/10356/166494
• Institution: Nanyang Technological University

Self-powered photodetectors with broadband and polarization-sensitive photoresponse are desirable for many important applications such as wearable electronic devices and wireless communication systems. Recently, two-dimensional (2D) materials have been demonstrated as promising candidates for self-powered photodetectors owing to their advantages in light–matter interaction, transport, electronic properties, and so on. However, their performance in speed, broadband response, and multifunction is still limited. Here, we report a PdSe2 photodetector with asymmetric van der Waals (vdWs) contacts formed by using a homojunction configuration. This device achieves a high responsivity approaching 53 mA/W, a rise/decay time of about 0.72 ms/0.24 ms, and a detectivity of more than 5.17 × 1011 Jones in the visible-near infrared regime (532–1470 nm). In addition, a linear polarization-sensitive response can be observed with an anisotropy ratio of 1.11 at 532 nm and 1.62 at 1064 nm. Furthermore, a strong anisotropic response endows this photodetector withoutstanding polarization imaging capabilities, realizing a contrast-enhanced degree of linear polarization imaging.Our proposed device architecture demonstrated the great potential of PdSe2-based asymmetric vdWs contacts for high-performance photodetectors operating without any external bias.