The Fabrication And Performance Of 1D/2D Junction Field Effect Transistor Based On MoS₂

As important members of two-dimensional layered materials,transition metal chalcogenides?TMDs?have gained extensive attention due to its unique physical and chemical properties.Among which,MoS₂ with suitable bandgap?1.2-1.8 eV?,relatively good air stability as well as fantastic optical and electrical properties has become a hot topic for researchers.The ultra-thin structure and relatively high room-temperature mobility make MoS₂ an ideal semiconductor to apply in field effect transistor?FET?and other micro-electronic devices.Most MoS₂ FETs use back-gate or top-gate with metal-oxide semiconductor?MOS?structure to modulate the carrier concentration of the channel.But the back-gate structure can't control an individual device on the substrate.The top-gate structure need deposition of the dielectric layer,which may do the damage to the surface of the channel.Here we built1D/2D heterojunction with p-type nanowire and n-type MoS₂.And we designed a new structure of junction field electric transistor?JFET?using the heterojunction.The 1D/2D JFET provides a new solution for MoS₂ FET design.The main research contents are list below:The MoS₂ nanosheet prepared by mechanical exfoliation and CuO nanowire prepared by copper foil oxidation were used to build the JFET,in which MoS₂ acts as channel material and CuO serves as gate.We compared the configuration of putting the nanowire underneath the MoS₂ and on the MoS₂.It was verified that the inverted gate-all-around configuration with CuO put underneath the MoS₂ nanosheet could provide a better gate controllability.For the purpose of improving the current density,we applied the back-gate voltage to modulate the carrier concentration of the channel,which means the dual-gate control was used.We creatively introduce the self-aligned graphene to stabilize the potential of the CuO nanowire gate and reduce the interference of the two gates effectively.We explored the application of the device in photodetection and logic circuit.On the basis of work above,we used Sb₂Se₃ nanowire to replace CuO nanowire serving as gate of the MoS₂ JFET.Different from the CuO,Sb₂Se₃ have a special crystal structure of one dimension.The dangling-bond-free surface of Sb₂Se₃ nanowire may reduce the density of traps and Coulomb scattering on the surface of the junction.The results show that it could reduce the sweep hysteresis of the JFET.We also explore the application of this Sb₂Se₃/MoS₂-1D/2D JFET in logic circuit.