In the present work, the effects of vacancy in graphene on the bonding strength, electronic characteristics and thermal conductance of Cu/graphene/Al interface are deeply studied by first-principles calculation. It is found that the introduction of appropriate vacancies could simultaneously enhance the Cu/graphene/Al interfacial bonding strength and thermal conductance. The Cu(111)/perfect graphene/Al(111) interfacial bonding strength is very low because of the limited interface charge transfer. However, when the vacancy is introduced in the graphene, the Cu(111)/graphene/Al(111) interfacial bonding strength could enhance several times, the enhancement effect increases with the vacancy concentration, and the increasement of vacancy area has a better effect for the enhancement of Cu(111)/graphene/Al(111) interfacial bonding strength at the same vacancy concentration. The reason why the vacancy in graphene could significantly improve the interfacial bonding strength is that the Cu-p and Al-p state of interfacial Cu and Al atom are more delocalized and could effectively hybridize with the p states of C atom near the vacancy in graphene. In addition, the introduction of vacancy could effectively increase the phonon density of states matching degree between the interfacial Cu, Al atoms and C atoms in graphene, and thus could effectively enhance the thermal conductance across the Cu(111)/graphene/Al(111) interface.

中文翻译：

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同时增强铜/石墨烯/铝界面结合强度和热导率的空位介导效应：第一性原理研究

在目前的工作中，通过第一性原理计算深入研究了石墨烯中空位对Cu/石墨烯/Al界面的键合强度、电子特性和热导率的影响。发现引入适当的空位可以同时提高Cu/石墨烯/Al界面结合强度和热导率。由于有限的界面电荷转移，Cu（111）/完美石墨烯/Al（111）界面键合强度非常低。然而，当石墨烯中引入空位时，Cu(111)/石墨烯/Al(111)界面键合强度可以增强数倍，增强效果随着空位浓度的增加而增加，在空位浓度相同的情况下，空位面积的增加对提高Cu(111)/石墨烯/Al(111)界面结合强度的效果更好。石墨烯中的空位能显着提高界面键合强度的原因是界面Cu和Al原子的Cu-p和Al-p态更加离域，可以有效地与石墨烯空位附近的C原子的p态杂化. 此外，空位的引入可以有效提高石墨烯界面Cu、Al原子和C原子的声子态密度匹配度，从而有效提高Cu(111)/石墨烯/Al(111 ） 界面。石墨烯中的空位能显着提高界面键合强度的原因是界面Cu和Al原子的Cu-p和Al-p态更加离域，可以有效地与石墨烯空位附近的C原子的p态杂化. 此外，空位的引入可以有效提高石墨烯界面Cu、Al原子和C原子的声子态密度匹配度，从而有效提高Cu(111)/石墨烯/Al(111 ） 界面。石墨烯中的空位能显着提高界面键合强度的原因是界面Cu和Al原子的Cu-p和Al-p态更加离域，可以有效地与石墨烯空位附近C原子的p态杂化. 此外，空位的引入可以有效提高石墨烯界面Cu、Al原子和C原子的声子态密度匹配度，从而有效提高Cu(111)/石墨烯/Al(111 ） 界面。