Cooling Scheme Of Black Phosphorus-Based Nanostructures Via Near-Field Radiative Heat Transfer

Black phosphorus(BP)is a kind of two-dimensional semiconductor material with excellent performance,and it has better performance than traditional bulk semiconductors under extreme size because of the characteristics of two-dimensional materials.As silicon-based field effect transistors have approached its physical limit,BP has the potential to become a new generation of semiconductor materials.However,the thermal conductivity of BP is very small,so we envisage utilizing the near-field radiative heat transfer(NFRHT)approach to cool the BP-based devices.NFRHT can break through the blackbody limit specified by the Stefan-Boltzmann law and can exceed the blackbody limit by several orders of magnitude due to the contributions of evanescent waves and surface modes.Utilizing the NFRHT approach to cool the BP-based devices not only can satisfy the requirement of heat dissipation,but also can avoid the impact on the BP-based devices due to contact.Considering the heat dissipation requirement of BP-based devices,the thermal conductivity of the cooling body should be very high so as to quickly conduct heat away.The paper mainly investigates NFRHT between the monolayer BP or BP ribbon arrays(BP RAs)and the graphene-covered Si C nanowire arrays(NWAs).BP may need to be tailored in practical applications,and BP RAs can be as a representative of the situation that needs to be tailored.Graphene is a kind of high thermal conductivity material and the surface plasmons that graphene excites can effectively enhance NFRHT.In addition,the properties of graphene can be easily adjusted by doping or applying bias voltage.Si C is also a kind of high thermal conductivity material and can excite surface phonon polaritons;Si C NWAs are a kind of hyperbolic metamaterial and can excite broadband hyperbolic phonon polaritons.We study the effects of the electron doping concentration of BP,the chemical potential of graphene,the volume fraction of Si C NWAs and the width of BP RAs on NFRHT through theoretical calculations.It can be found that when the chemical potential of graphene and the volume fraction of the Si C NWAs are relatively small,the NFRHT is relatively strong.In practical applications,the chemical potential of graphene and the volume fraction of Si C NWAs can be adjusted to enhance NFRHT according to the electron doping concentration of BP and the width of BP RAs.The research has important reference value for the heat dissipation problem of BP-based devices,and it is also of great significance for the NFRHT research between different materials.