The Opto-electronic Property And Thermal Stability Study Of Two Dimensitional Molybdenum Disulphide

Two-dimensional layered transition metal dichalcogenide?TMD?displays a wide range of application potential in electronic device,photovoltaic device,energy storage and sensing.As one of the transition metal dichalcogenide,the single-layer molybdenum disulfide?MoS₂?is direct bandgap semiconductor regarded as an alternate material that can replace the traditional silicon in the field of electronic device applications due to its excellent gate control,large on-off current ratio,high field effect mobility as well as low standby power dissipation.The photodetector based on mechanical exfoliated single-layer MoS₂ opens up a new direction for the future multifunctional optoelectronic devices due to the excellent properties.The study of the photoelectrical properties of two-dimensional MoS₂ is one of the hotspots in the field of materials.In this paper,we introduce the properties of MoS₂ and also the preparation methods and the characterization methods of the two dimensional MoS 2 material.Otherwise,we introduce the application of two-dimensional MoS₂ materials in the field of transistors,optoelectronic devices and new energy.Mo S 2 is an appealing material for optoelectronics because of its good transmission,flexibility,easy to prepare,and good compatibility with different substrate,compared with the traditional semiconductors.Different substrates with different conductivity,which will apply different strain and induce doping upon MoS₂,so on different substrates MoS₂ will exhibits different electrical and optical properties.The experiment results demonstrate that MoS₂ exhibits the metal property on different substractes.The experiment results also demonstrate that the photon-current of MoS₂ optoelectronic device increases with the transverse electronic field increases.Besides,the optoelectronic properties of graphene/MoS₂ heterostructure device is obtained in this paper.The heterostructure optoelectronic detector expresses higher photo-current,shorter response time,and higher responsivity compared with the MoS₂ optoelectronic detector,which demonstrate the heterostructure optoelectronic detector is more stable and functional.The study of the substrate effect and heterostructure optoelectronic detector will promote the understanding of optoelectronic properties of MoS₂.The optoelectronic properties of MoS₂ are obviously affected by MoS₂ layer.To better understand the properties of MoS₂ devices,it is necessary to determine the layer of MoS₂ quickly and accurately.Atomic force microscopy?AFM?is a direct technique to identify the layer number of MoS₂ nanosheets,however the result is affected by the adsorbed molecules on MoS₂ nanosheet.We find a method which can fast,non-destructive and currently to determine the layer of MoS₂.In this work,it is found that the Raman area ratio between the Si peak from Si O2/Si substrate underneath TMD nanosheets?ASi?and that from bare Si O2/Si substrate?ASi?0??,ASi/ASi?0?,can be using to accurately identify the layer number of MoS 2 nanosheet.ASi/ASi?0?is then calculated using the Fresnel equations,the theory result is good agreement with the experimental result.Identification of layer of MoS₂ will facilitate understanding of the exotic properties of MoS₂.The thermal stability of electronic devices is a very important factor to affect device performance.However,there are many problems with the study of the thermal stability of molybdenum sulfide,which has not been discussed in detail.In this work,the oxidation kinetic of monolayer MoS₂ in air was studied by Raman spectroscopy and the oxidation energy of monolayer MoS₂ in air was also obtained.Our research found that the adsorbed H2 O and/or O2 molecules can induce hole doping in monolayer MoS₂,and the adsorbed water molecules will affect the oxidation process of single layer MoS₂.The study of thermal stability made us better understand the oxidation kinetic process of MoS₂,and the study of doping will help us fully understand the carrier transport properties based on the Mo S 2 field effect transistor.