Gate-Modulated and Polarization-Sensitive Photodetector Based on the MoS2/PdSe2 Out-Of-Plane Van Der Waals Heterostructure

Photodetectors with good polarization detection ability are promising in many applications, such as remote sensing imaging and environmental monitoring. However, the traditional polarization detection systems fall short in meeting integration demands of the integrated-circuits field due to additional optical elements. The emerging 2D materials with in-plane anisotropic structures provide a possible method to fabricate remarkable polarization detectors. Modulating the band structure by gate voltage is an important strategy for developing optoelectronic devices. Herein, a polarized photodetector based on PdSe2/MoS2 out-of-plane heterojunction is fabricated. Due to its unique out-of-plane heterostructure, the device exhibits excellent photoresponse characteristics and polarization sensitivity, including an excellent responsivity of 10.19A/W, an extremely high external quantum efficiency of 2429%, a fast rise/decay time of 68/192 mu s, and a high photocurrent anisotropy ratio of 3.09. Based on the adjustment of the built-in electric field through gate voltage, the performance of the device can be accordingly modulated. As the gate voltage increases from -30 to 30 V, the responsivity gradually increases from 7.5 to 13A/W and the detectivity increases from 1.53 to 2.63 x 10(9)Jones. Finally, its olarization imaging ability is demonstrated at different polarization angles. The findings indicate that PdSe2/MoS2 devices exhibit significant potential for polarized photoelectric detection.