Characteristics Of Acoustic Phonon Transport And Thermal Conductance In Biomass Graphene Nanoribbons

With the rapid development of new materials technology and nanotechnology,nano scale devices has become an inevitable trend.Due to the size effect of nano devices,they show the novel physical properties and wide application prospect.In the low dimensional quantum structure,thermal conductivity is quantized by quantum,which limits the phonons in the excitation and transport has been restricted,which leads to low dimensional nano materials,its thermal conductivity is greatly reduced compared with bulk materials.In addition,with the electronic components in the circuit gradually miniaturization,high integration,which leads to quantum the device is highly integrated in the group work the thermal power density increases rapidly,the thermal requirements of these quantum structures with high rate so as to accelerate the heat,avoid these quantum devices the nature of work is not stable or even failure.Therefore,the quantum thermal transport properties has attracted much attention.In this paper the structure of graphene nanoribbons,properties and preparation methods are briefly introduced,compared with the raw material for preparation of graphene with other materials as raw materials,preparation of graphene has abundant raw materials from biomass,low cost and mass production characteristics,which satisfies the world of graphene materials demand.Increase the market;reviewed and of low dimensional nanomaterials in phonon transport and thermal conductance characteristics;and then briefly introduces the theory and method of modeling method of transport properties of thermal transmission;calculation model of zigzag graphene finally we established a number of channels with different boundary conditions with rough and multi curved zigzag graphene nanobelts,The thermal transport properties of elastic acoustic phonons of these two models are investigated by using the nonequilibrium Green's function method.Research on multi channel with different roughness boundary conditions of zigzag graphene nanoribbons.The results showed that with the increase of temperature,the number of channels of zigzag graphene nano belt in effect of heat transport is very obvious,while maintaining the energy output channels in graphene total chain number unchanged,with increasing graphene channel number that can reduce the thermal conductivity of each energy output channel.The most close to the energy input energy output channel of the heat sink thermal conductivity maximum energy output channel,and as far as the minimum thermal conductivity;energy output channel is located in the middle of the thermal conductivity and its columns and each output channel structure parameters are closely related,although the structure parameters of other channels change,while the total number of graphite chain energy output channels unchanged,changes in the structure parameters of other channels did not affect the relative position of the energy input channel and output channel,so these changes almost has no effect on the phonon transmission probability in the channel.The results show that the modulation of graphene nanoribbons structure and bandwidth can be used to control the thermal conductivity,and recently as far as the energy output of the channel thermal conductivity is only related with the energy output channel structure parameters respectively.In addition,the results of the study show that:compared with the ideal boundary structure,rough edge structure can effectively adjust the thermal conductivity of each channel,with the increasing of temperature,high frequency and short wavelength phonons are excited,the Some are vulnerable to phonon scattering effects.The rough boundary scattering effect due to phonon transmission probability of each output channel effects vary,leading to thermal energy input and output and the recent end of the intermediate output terminal to output decreased significantly;thermal conductivity and energy input of the farthest end but therefore enhanced.The boundary,more rough,the total thermal conductivity decreased more obviously.So our study found that:the thermal conductivity properties and energy output channel multi-channel graphite chain chain,chain number in each channel of graphite and rough process of edge structure is closely related.The transport properties through the study found lost many corners of zigzag graphene nanoribbons:thermal coupling effect of chain number and the number of corners of the graphene nanoribbons can determine the thermal transport properties,while maintaining the number of total energy output curve under the same conditions,study and compare the effects of different graphene nano energy input chain number meters with the biomass of graphene nanoribbons elastic acoustic phonon transport,the results of the study found that the number of the chain of the graphene nanoribbons,energy output channel transmission coefficient is greater.In addition,while maintaining the energy input and output chain total number under the same conditions,study and compare a corners,two corners,three corners of the biomass graphene nanoribbons bomb The results show that the more the number of bends in graphene nanoribbons,the smaller the transmission coefficient of the energy output channel.Finally,through a comparative study on the properties of the multi-channel and multi curved graphene phonon heat transport found that due to the different needs of the structure of industrial products in the application,if there is a multi port output heat or heat demand,you need to take the structure of multi channel graphene nanoribbons structure;and if there is a heat or heat bend output requirements,you need to consider multiple curves of graphene nanoribbons structure;in practical applications,multi channel graphenenanoribbon is more than the curve of graphene nanoribbons used more,this is because the graphene nano channel with the energy output of at least two and above,and thus more selective high,and the curve of graphene nano Since the band has only a single energy output,the selectivity will be much lower.