Template Synthesis Of GaN Nanosheets And Theoretical Study Of G-GaN-Based Heterostructure

The successful preparation of graphene has opened the door to the world of two-dimensional materials.The two-dimensional material is sheet-like structure with the thickness of atomic layer.It has good mechanical properties,unique electronic,and optical properties.Therefore,two-dimensional materials can be applied in fields such as energy storage devices and electronic devices with great functional versatility.As a member of the two-dimensional material family,two-dimensional GaN has many excellent physical properties,making it potential applications in ultraviolet emitting devices,photocathodes,hydrogen storage materials,and high-power optoelectronic devices.Based on previous work,this article studies the preparation of two-dimensional GaN nanosheets,and the theoretical study of two-dimensional g-GaN-based heterostructure was also investigated.Drawing on the idea of template method,the well-shaped ?-Ga2O3 nanosheets were firstly synthesized as templates by hydrothermal method,and then the effects of reaction temperature,reaction time,and NH3 gas flow rate on the morphology of the prepared GaN nanosheets were studied by the controlled variable method,and the optimal process conditions for the preparation of GaN nanosheets were obtained as follows:reaction temperature of 850?,NH3 flow rate of 100sccm,and the reaction time was 30 min.The GaN nanosheets prepared under the optimal conditions were further analyzed by EDS,XRD,XPS,and TEM tests,and the test results show that the GaN nanosheet samples prepared under the optimal process conditions are hexagonal wurtzite structure with high purity and good crystallinity.In addition,we constructed the Graphene-GaN-Graphene(G-GaN-G)sandwich heterostructure,and the electronic and optical properties were investigated theoretically based on first-principles calculations.The calculation results show that the binding energy is maximum when the interlayer distance do is 3.1 89 A.Further,the energy and geometry of the heterostructure at 300 K is simulated by molecular dynamics method,and it is found that the geometry only undergoes slight deformation and the energy of the system is basically stable,so it is proved that the G-GaN-G heterostructure is relatively stable at room temperature;the G-GaN-G heterostructure is p-type Schottky contact,which retains the properties of intrinsic g-GaN and graphene in its electronic and optical properties;the band of g-GaN shifts downward as a whole when a tensile vertical strain is applied,and the Schottky contact changes from p-type to n-type when the tensile vertical strain is greater than 0.3 A;biaxial strain can effectively regulate the electronic and optical properties of the G-GaN-G heterostructure,and therefore,the strain can be applied to modulate the electronic and optical properties of G-GaN-G.The results of this part research suggest that G-GaN-G sandwich heterostructures are promising for UV photodetectors and Schottky devices.