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

Abstract

Reducing the Schottky barrier height (SBH) of metal-MoS interface with no deteriorating the intrinsic properties of MoS channel layer is crucial to realize the high-performance MoS 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 MoS channel layer. Results demonstrate that no matter the types of concentrations and dopants the intrinsic electronic structure, low electron effective mass of MoS channel layer, and the weak Fermi level pinning effects of metal/BN-MoS interfaces are preserved and not deteriorated. More importantly, the n- and p-type SBHs of metal/BN-MoS 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/BN-MoS interface and the p-type SBH of doped Pt/BN-MoS 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 MoS nanodevices with negligible SBHs.

Progress in Contact, Doping and Mobility Engineering of MoS2: An Atomically Thin 2D Semiconductor

“…Another study by Su et al suggested that the SBH for both electrons and holes in the metal/hBN/MoS 2 contact geometry can be decreased or even completely eliminated by doping the hBN buffer layer with high concentrations of Li (electron-poor) and O (electron-rich) dopants, respectively, and that this effect can be more pronounced when the doped-hBN buffer layer spreads all over the MoS 2 device surface. Moreover, the authors predicted that both the intrinsic nature of the MoS 2 and the weak FLP effects at the metal/hBN/MoS 2 interface are preserved irrespective of the dopant type and concentration [245].…”

Au Catalyst-Modified MoS2 Monolayer as a Highly Effective Adsorbent for SO2F2 Gas: A DFT Study

“…12,13 Metal-modified MoS 2 materials have been investigated for application in gas molecules adsorption, which shows a broad application prospect. 14−16 Furthermore, based on the first-principles calculations, researchers verified that a noble metal-modified MoS 2 monolayer shows great adsorption ability toward specific gas molecules. 15,17 For MoS 2 modification, Wang et al studied the adsorption and diffusion of noble metal atoms on MoS 2 based on the density functional theory (DFT).…”

Giant proximity exchange and valley splitting in transition metal dichalcogenide/ hBN /(Co, Ni) heterostructures

“…In the former case, studying the dependence of the Schottky barrier on the used electrode is crucial [64][65][66][67][68][69][70][71] . It turns out that a hBN tunnel barrier is also a good choice here, preserving the intrinsic properties of the TMDC while enormously reducing the contact resistance 65,[72][73][74] . Also other insulating barriers, such as TiO 2 , MgO or Al 2 O 3 [75][76][77][78][79] are promising candidates, where the thickness of the barrier plays an important role for the efficiency of spin injection.…”