Lin-Bao Luo, Di Wang, Chao Xie,* Ji-Gang Hu,* Xing-Yuan Zhao, and Feng-Xia Liang*

Abstract:In this study, we are presenting a sensitive infrared photodetector (IRPD) composed of germanium nanocones (GeNCs) array and PdSe₂ multilayer, which is obtained by a straightforward selenization approach. The as-assembled PdSe₂/GeNCs hybrid heterojunction exhibited obvious photovoltaic behavior to 1550 nm illumination, which renders the IRPD a self-driven device without external power supply. Further device analysis revealed that the PdSe₂/GeNCs hybrid based IRPD exhibited high sensitivity to 1350, 1550, and 1650 nm illumination with excellent stability and reproducibility. The responsivity and EQE was as high as 530.2 mA/W and 42.4%, respectively. Such a relatively good device performance is related to the strong light trapping effect of GeNCs array, according to our theoretical simulation based on finite-difference time-domain (FDTD). It is also found that the IRPD showed an abnormal sensitivity to IR illumination with wavelength of 2200 nm. Finally, the present individual IRPD can also record the simple “F” image produced by 1550 nm, suggesting the promising application of the PdSe₂/GeNCs hybrid device in future infrared optoelectronic systems.