| 초록 |
2D atomic-layered materials such as graphene and transition metal dichalcogenides (TMDs) have attracted much attention as promising materials for chemical and optical sensing devices owing to their extraordinary physical properties. In this presentation, we firstly will discuss diverse considerations of 2D nanomaterials necessary for high performance chemical sensing applications. We will show unique 2D heterostructure designs based chemical sensor such as Graphene/MoS2 and NbSe2/WSe2 with NbxW1−xSe2 transition alloy junction and also provide approaches to improve critical sensing performance including sensitivity, selectivity and stability through surface decoration of metal nanoparticles or substitutional doping of metallic atoms to 2D lattice. Secondly, we will introduce a growth technique to directly prepare 2D materials onto conventional semiconductor substrates, enabling low-temperature, high-throughput, and large-area capability. In order to achieve this goal, we successfully developed an atmospheric-pressure plasma-enhanced chemical vapor deposition (AP-PECVD) technique, which could grow MoS2 and WS2 multilayers directly onto PET flexible substrate as well as 4-inch Si substrates at temperatures of ＜200 °C. The as-fabricated MoS2/Si and WS2/Si heterojunctions exhibited large and fast photocurrent responses under illumination of a green light. The measured photocurrent was linearly proportional to the laser power, indicating that trapping and detrapping of the photogenerated carriers at defect states could not significantly suppress the collection of photocarriers. All the results demonstrated that our AP-PECVD method could produce high-quality TMD/Si 2D–3D heterojunctions for optoelectronic applications. |
