Vertically Coupling ZnO Nanorods onto MoS2 Flakes for Optical Gas Sensing

Abstract

Hybrid structures composed of layered one-dimensional (1D) and two-dimensional (2D) materials opened new perspectives and opportunities through the build-up of hetero-junctions with versatile layered structures and led to fascinating fundamental phenomena and advanced devices. We succeeded in depositing by magnetron sputtering vertically aligned 1D ZnO nanorods on 2D MoS2 flakes obtained by exfoliation, preserving the structure of the 2D materials. The photoluminescence (PL) optical properties of the hybrid structure were assessed towards developing a contactless optical chemical sensor.

Optical Properties of 1D ZnO/MoS\(_2\) Heterostructures Synthesized by Thermal Evaporation Method

“…A relatively narrow and weak emission band in the near-ultraviolet region (NUV) peaked at around 380 nm and a broad emission band in the visible from 420 -700 nm. The NUV band is well-known and could be attributed to the NBE emission of ZnO [29,30]. The broad visible emission peaked at around 507 nm is defect-related emissions (DE) such as oxygen antisites (OZn), interstitial oxygen (Oi), oxygen vacancy (Vo) in the ZnO nanowires, and ZnO/MoS 2 heterostructures [9,23].…”

Tuning nanowire lasers via hybridization with two-dimensional materials

“…[20][21][22] Previous studies on 1D-2D heterostructures formed by semiconductor NWs and layered materials focused mainly on tuning the non-linear optical properties of layered materials, 23 enhancing plasmonic lasing on metallic substrates, 5,6 and realizing high-responsivity photodetectors 24,25 and high-sensitivity gas sensors. [26][27][28] However, to the best of our knowledge, to date no comprehensive study on the lasing properties of hybrid NW and layered materials heterostructures was published. In addition, most of such hybrid devices were fabricated either by epitaxial growth of NWs on 2D templates, [29][30][31][32] or by drop-casting a NW dispersion on a substrate and subsequent placement of the layered material on top of it, typically with a stage-assisted 33 polydimethylsiloxane (PDMS) transfer or similar lift-off processes.…”

2D–1D mixed-dimensional heterostructures: progress, device applications and perspectives

“…The device can respond sensitively with a resistance decrease by 37% in 3.5 s under 2500 sccm O 2 exposure in air, and it would recover back with a short period of 0.15 s. Meanwhile, the resistance of sensor would drastically increase by 1280% within 12/0.15 s response/recovery times at H 2 atmosphere (figures 14(a)-(c)). Besides, similar structures consisting of 2D MoS 2 -1D ZnO have also been widely explored to detect trace NO 2 gas [128][129][130].…”