Controllable p-type doping of monolayer MoS2 with tantalum by one-step chemical vapor deposition. Issue 19 (4th May 2022)

• Record Type: Journal Article
• Authors: Li, Mengge; Wu, Xiaoxiang; Guo, Wenxuan; Liu, Yali; Xiao, Cong; Ou, Tianjian; Zheng, Yuan; Wang, Yewu
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 19(2022)
• Page Start: 7662
• Page End: 7673
• Publication Date: 2022-05-04
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc01045c
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The synthesis of controllable pure and p-type in situ Ta-doped monolayer MoS2 with different doping concentrations via a one-step salt-assisted chemical vapor deposition (CVD) method with systematic characterization studies is reported. Abstract : Molybdenum disulfide (MoS2 ) is natively an n-type semiconductor due to omnipresent electron-donating sulfur vacancies, indicating that the synthesis of high-quality p-type semiconducting MoS2 has been challenging. Substitutional doping has been proved to be an effective and stable approach to manipulate the electronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDs). Group five transition metals such as vanadium (V), niobium (Nb), and tantalum (Ta) are potential alternative p-type dopants. In particular, Ta has more intriguing properties than V and Nb, resulting in exceptional performance in many applications. Herein, we have predicted the p-type doping effect of Ta-doped MoS2 with the Fermi-level shifting to the valence band maximum based on density functional theory. The large-area monolayer p-type Ta-doped MoS2 with different doping concentrations has been synthesized via a simple one-step NaCl-assisted CVD method. The energy-dispersive X-ray spectroscopy (EDS) characterization indicated that the highest Ta doping concentration can be up to 1.28% atomic percent by controlling the proportion of Ta with respect to the Mo precursor. The room-temperature and temperature-dependent electrical measurements of Ta-doped MoS2 transition-effect-transistors (FETs) all show an ambipolar behavior and present an n- to p-type conversion with increasing Ta doping concentrations. The successful synthesis of p-type Ta-doped MoS2 in this study offers opportunities for advanced technologies and fundamental studies and provides significant potential for future electronic and optoelectronic applications of 2D materials.