Ferroelectrically Enhanced Polarization-Sensitive AuNPs-Deposited α-In<sub>2</sub>Se<sub>3</sub>/PdSe<sub>2</sub> Photodetector with Ultrahigh Photoresponsivity and Detectivity
Hyeok Jun Jin, Cheolmin Park, Khang June Lee, Mingu Kang, Sung‐Yool Choi
Abstract
To enhance the detectivity and overall performance of the device, this study presents a polarization-sensitive photodetector by leveraging the anisotropic in-plane crystal structures of α-In 2 Se 3 and PdSe 2 . By incorporation of Au nanoparticles (AuNPs) and exploiting the ferroelectrically controllable polarization of α-In 2 Se 3, the proposed photodetector achieves exceptional polarization detection capabilities. Specifically, aligning the poling direction of α-In 2 Se 3 with the a -axis of PdSe 2 and the incorporation of AuNPs yield a remarkable photoresponsivity of 4137 A/W and a detectivity of 1.158 × 10 13 Jones at a near-infrared wavelength of 980 nm, along with a rapid response time of 29 μs. Polarization sensitivity of the device was significantly enhanced by a factor of 5.9, from 2.56 to 15.1, through the poling of the two-dimensional ferroelectric α-In 2 Se 3 . These findings represent a substantial advancement in the development of high-performance, polarization-sensitive photodetectors using atomically thin 2D materials, offering new opportunities for next-generation optoelectronic applications.