Controllable p-type doping of monolayer MoS2 with tantalum by one-step chemical vapor deposition
Controllable p-type doping of monolayer MoS2 with tantalum by one-step chemical vapor deposition
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DOI：
10.1039/d2tc01045c
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发表时间：
2022-04-20
影响因子：
6.4
通讯作者：
Wang, Yewu
中科院分区：
文献类型：
--
作者：
Li, Mengge;Wu, Xiaoxiang;Wang, Yewu
二硫化钼（MoS2）是天然的n型半导体，由于无处不在的给电子硫空位，这表明高质量p型半导体MoS2的合成具有挑战性。取代掺杂是一种有效而稳定的调控二维过渡金属二硫属化合物电子性质的方法。第五族过渡金属如钒（V）、铌（Nb）和钽（Ta）是潜在的替代P型掺杂剂。特别是，Ta具有比V和Nb更有趣的特性，在许多应用中具有出色的性能。在此，我们已经预测的p型掺杂的Ta掺杂的MoS2的费米能级移动到价带最大值的基础上的密度泛函理论。采用简单的一步NaCl辅助CVD法制备了不同掺杂浓度的单层p型Ta掺杂MoS2薄膜。能量色散X射线光谱（EDS）表征表明，通过控制Ta相对于Mo前体的比例，最高Ta掺杂浓度可以高达1.28%原子百分比。Ta掺杂的MoS2过渡效应晶体管（FET）的室温和随温度变化的电学测量都显示出双极行为，并且随着Ta掺杂浓度的增加呈现n型到p型的转换。本研究中p型Ta掺杂MoS2的成功合成为先进技术和基础研究提供了机会，并为2D材料的未来电子和光电应用提供了巨大的潜力。
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.