Wang Zixuan, Zhao Xiaoxu, Yang Yuekun, Qiao Lei, Lv Lu, Chen Zhang, Di Zengfeng, Ren Wei, Pennycook Stephen J, Zhou Jiadong, Gao Yanfeng
School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China.
Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore.
Small. 2020 May;16(20):e2000852. doi: 10.1002/smll.202000852. Epub 2020 Apr 22.
Tuning bandgap and phases in the ternary 2D transition metal dichalcogenides (TMDs) alloys has opened up unexpected opportunities to engineer optoelectronic properties and explore potential applications. In this work, a salt-assisted chemical deposition vapor (CVD) growth strategy is reported for the creation of high-quality monolayer W Re S alloys to fulfill a readily phase control from 1H to DT by changing the ratio of Re and W precursors. The structures and chemical compositions of doping alloys are confirmed by combining atomic resolution scanning transmission electron microscopy-annular dark field imaging with energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy, matching well with the calculated results. The field-effect transistors (FETs) devices fabricated based on 1H-W Re S monolayer exhibit a n-type semiconducting behavior with the mobility of 0.4 cm V s . More importantly, the FETs show high-performance responsivity with a value of 17 µA W in air, which is superior to that of monolayer CVD-grown WS . This work paves the way toward synthesizing monolayer ternary alloys with controlled phases for potential optoelectronic applications.
调整三元二维过渡金属硫族化合物（TMDs）合金的带隙和相，为设计光电特性和探索潜在应用带来了意想不到的机遇。在这项工作中，报道了一种盐辅助化学沉积气相（CVD）生长策略，用于制备高质量的单层W-Re-S合金，通过改变Re和W前驱体的比例实现从1H到DT的易控相转变。通过将原子分辨率扫描透射电子显微镜-环形暗场成像与能量色散X射线光谱（EDS）和X射线光电子能谱相结合，证实了掺杂合金的结构和化学成分，与计算结果吻合良好。基于1H-W-Re-S单层制备的场效应晶体管（FETs）器件表现出n型半导体行为，迁移率为0.4 cm² V⁻¹ s⁻¹。更重要的是，FETs在空气中具有17 µA W⁻¹的高性能响应率，优于单层CVD生长的WS₂。这项工作为合成具有可控相的单层三元合金以用于潜在的光电应用铺平了道路。
