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 (MoS 2 ) nanoflakes and zinc oxide (ZnO) quantum dots (QDs) on the Au core−shelled AuPd hybrid NPs (HNPs), namely, the MoS 2 *ZnO/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 MoS 2 nanoflakes also successfully absorb the high-energy photons, offering additional photocarriers. The optimized device demonstrates an increased photocurrent (I ph ) of 1.49 × 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 × 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 MoS 2 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 MoS 2 *ZnO/HNP blended active layer.

Heterostructures made from bone-like plasmonic Au nanoantennas and ZnO quantum dots for broadband photodetectors

“…The pure ZnO QDs film shows a strong absorption band in the UV region because of the relatively wide band gap (B3.37 eV) for ZnO. 46 While the pure BLAuNAs exhibit two absorption bands: a strong band below 500 nm (because of the interband transition of its d-band electrons to its conduction sp-band) and an additional band in the region of 500B600 nm (because of their plasmon) (Fig. 4a).…”

“…Clearly, BLAuNA2/ZnO heterostructures photodetector exhibits a largely improved SNR because of their large I ph and extremely low I d , indicating its outstanding capability to discern optical information from the dark noise. To quantitatively evaluate the photoresponse performance of four photodetectors, the responsivity (R), detectivity (D), and external quantum efficiency (EQE) were calculated using the following equations 46,49,50…”

Tailoring Exciton Diffusion Length in ZnO@MoS2 Core–Shell/Polyaniline Nanocomposite Films and Photocurrent Generation Applications

“…Heterostructures of different semiconductors have attracted great interest due to their comparative energy levels for the effective separation of charge carriers. − Selective desirable requirements can be achieved by changing the composition of constituent materials in a heterostructure and the creation of lattice strain highly affects the generation and migration of excitons. Photoinduced applications require an effective separation of charge carriers.…”

Surmounting the interband threshold limit by the hot electron excitation of multi-metallic plasmonic AgAuCu NPs for UV photodetector application

“…[2][3][4][5][6][7] Advanced UV-PD devices require high photocurrent, fast response, low power consumption and stable operation. [9][10][11][12][13] Recently, the integration of various photoactive materials such as metallic nanoparticles (NPs), semiconductor quantum dots and 2D materials into a hybrid PD design has been gaining increased attention, which can offer innovative opportunities to overcome the performance limitation of conventional UV PDs. [13][14][15][16][17] The localized surface plasmon resonance (LSPR), namely, the resonant oscillation of free electrons on metallic NPs, induces interesting phenomena such as strong absorption, scattering, localized e-fields and hot electron injection, which can offer a promising route to enhance the performance of UV PDs.…”

“…[9][10][11][12][13] Recently, the integration of various photoactive materials such as metallic nanoparticles (NPs), semiconductor quantum dots and 2D materials into a hybrid PD design has been gaining increased attention, which can offer innovative opportunities to overcome the performance limitation of conventional UV PDs. [13][14][15][16][17] The localized surface plasmon resonance (LSPR), namely, the resonant oscillation of free electrons on metallic NPs, induces interesting phenomena such as strong absorption, scattering, localized e-fields and hot electron injection, which can offer a promising route to enhance the performance of UV PDs. 16 For example, the integration of chemically synthesized Au NPs on a semiconductor substrate exhibited the amplification of photoresponsivity due to the injection of hot electrons into the conduction band of the active layer.…”