Promising Approach for High-Performance MoS₂ Nanodevice: Doping the BN Buffer Layer to Eliminate the Schottky Barriers

Reducing the Schottky barrier height (SBH) of metal-MoS₂ interface with no deteriorating the intrinsic properties of MoS₂ channel layer is crucial to realize the high-performance MoS₂ nanodevice. To realize this expectation, a promising approach is present in this study by doping the boron nitride (BN) buffer layer between metal electrode and MoS₂ channel layer. Results demonstrate that no matter the types of concentrations and dopants the intrinsic electronic structure, low electron effective mass of MoS₂ channel layer, and the weak Fermi level pinning effects of metal/BN-MoS₂ interfaces are preserved and not deteriorated. More importantly, the n- and p-type SBHs of metal/BN-MoS₂ interfaces are significantly reduced by the electron-poor and -rich dopants, respectively, when the doped BN buffer layer spreads all over the nanodevice, which is in contrast to the traditional doping rule. Moreover, both the n- and p-type SBHs are further decreased and even eliminated when the concentrations of dopants increase. The n-type SBH of doped Au/B_xN-MoS₂ interface and the p-type SBH of doped Pt/BN_x-MoS₂ interface can be reduced to -0.21 and -0.61 eV by doping with high concentrations of Li and O, respectively. This theoretical work provides an effective and promising method to realize high-performance MoS₂ nanodevices with negligible SBHs.