MoS2 Nanoflake and ZnO Quantum Dot Blended Active Layers on AuPd Nanoparticles for UV Photodetectors

Abstract

A hybrid UV photodetector incorporating a blended active layer of molybdenum disulfate (MoS2) nanoflakes and zinc oxide (ZnO) quantum dots (QDs) on the Au core-shelled AuPd hybrid NPs (HNPs), namely, the (MoS2ZnO)-Zn-*/HNP configuration, is demonstrated for the first time. In the proposed configuration, the hot carriers generated by the strong localized surface plasmon resonance (LSPR) of Au-shelled AuPd HNPs can be effectively collected at the ZnO QD's conduction band. The blended MoS2 nanoflakes also successfully absorb the high-energy photons, offering additional photocarriers. The optimized device demonstrates an increased photocurrent (I-ph) of 1.49 x 10(-3) A at 10 V under 54.9 mW/mm(2), which offers improved performance parameters of a photoresponsivity (R) of 2,525 mA/W, a detectivity (D) of 7.251 x 10(11) jones, and an external quantum efficiency (EQE) of 813% at 0.34 mW/mm(2). The result is one of the best ZnO-based photodetectors demonstrated so far. The enhanced photocurrent is due to the greater photocarrier injections by the blended active layer of MoS2 nanoflakes and ZnO QDs on the Au-shelled AuPd HNPs. The finite-difference time-domain (FDTD) simulation confirms the significantly increased maximum local e-field intensity and hotspots of the (MoS2ZnO)-Zn-*/HNP blended active layer.