作者:Dmitriy A. Chareev、Polina Evstigneeva、Dibya Phuyal、Gabriel J. Man、Håkan Rensmo、Alexander N. Vasiliev、Mahmoud Abdel-Hafiez
DOI:10.1021/acs.cgd.0c00980
日期:2020.10.7
Due to their physical properties and potential applications in energy conversion and storage, transition-metal dichalcogenides (TMDs) have garnered substantial interest in recent years. Among this class of materials, TMDs based on molybdenum, tungsten, sulfur, and selenium are particularly attractive due to their semiconducting properties and the availability of bottom-up synthesis techniques. Here we report a method which yields high-quality crystals of transition-metal diselenide and ditelluride compounds (PtTe2, PdTe2, NiTe2, TaTe2, TiTe2, RuTe2, PtSe2, PdSe2, NbSe2, TiSe2, VSe2, ReSe2) from their solid solutions, via vapor deposition from a metal-saturated chalcogen melt. Additionally, we show the synthesis of rare-earth-metal polychalcogenides and NbS2 crystals using the aforementioned process. Most of the crystals obtained have a layered CdI2 structure. We have investigated the physical properties of selected crystals and compared them to state of the art findings reported in the literature. Remarkably, the charge density wave transition in 1T-TiSe2 and 2H-NbSe2 crystals is well-defined at TCDW ≈ 200 and 33 K, respectively. Angle-resolved photoelectron spectroscopy and electron diffraction are used to directly access the electronic and crystal structures of PtTe2 single crystals and yield state of the art measurements.
由于其物理特性和在能量转换与储存方面的潜在应用,过渡金属二硫属化物(TMDs)近年来引起了广泛关注。在这一类材料中,基于钼、钨、硫和硒的TMDs因其半导体特性和自下而上合成技术的可获得性而特别具有吸引力。本文报告了一种方法,通过从金属饱和硫属熔体中蒸发沉积,从其固溶体中得到高质量的过渡金属二硒化物和二碲化物(PtTe2、PdTe2、NiTe2、TaTe2、TiTe2、RuTe2、PtSe2、PdSe2、NbSe2、TiSe2、VSe2、ReSe2)晶体。此外,我们还展示了利用上述工艺合成稀土金属多硫属化物和NbS2晶体的方法。所获得的大多数晶体具有层状CdI2结构。我们研究了选定晶体的物理性质,并与文献中报道的最先进研究成果进行了比较。值得注意的是,在1T-TiSe2和2H-NbSe2晶体中,电荷密度波转变在TCDW分别约为200K和33K时很好地定义。角分辨光电子能谱和电子衍射被用于直接获取PtTe2单晶的电子和晶体结构,并提供了最先进的测量结果。