Vertically Coupling ZnO Nanorods onto MoS2 Flakes for Optical Gas Sensing

Guido Faglia,Federica Rigoni,Thi Thanh Le Dang,Camilla Baratto,Matteo Ferroni,Maurizio Donarelli

doi:10.3390/chemosensors8010019

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.

Highlights

Two-dimensional (2D) materials have received increasing attention due to their unusual electrical, optical, and mechanical characteristics; coupling active one-dimensional (1D) and 2D materials is opening new and unexpected research scenarios and technological breakthroughs [1,2,3,4,5,6]. researchers are fascinated with graphene as compared to other 2D materials, the absence of a bandgap leads to its limited use in optical applications
Researchers are fascinated with graphene as compared to other 2D materials, the absence of a bandgap leads to its limited use in optical applications
transition metal dichalcogenides (TMDCs) have been widely studied for decades, their role as near-atomically thin materials is new: some TMDCs, such as Mo and W dichalcogenide compounds, show indirect-to-direct bandgap transition when exfoliated from a layered bulk crystal to a single layer, drawing massive interest for applications in optical and photovoltaic devices

Summary

Introduction

Researchers are fascinated with graphene as compared to other 2D materials, the absence of a bandgap leads to its limited use in optical applications. Two-dimensional transition metal dichalcogenides (TMDCs), such as MoS2 , WSe2 , and WS2 , are planar crystals made of one or a limited number of TMDC unit cells, possessing plentiful electronic, optical, mechanical, and chemical properties [7]. TMDCs have been widely studied for decades, their role as near-atomically thin materials is new: some TMDCs, such as Mo and W dichalcogenide compounds, show indirect-to-direct bandgap transition when exfoliated from a layered bulk crystal to a single layer (for instance, MoS2 bandgap ranges from 1.3 eV, indirect, in the bulk phase, to 1.8 eV, direct, in the monolayer phase), drawing massive interest for applications in optical and photovoltaic devices.

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