Quasi-one-dimensional (quasi-1D) van der Waals materials are an emerging frontier in nanoscience, offering highly anisotropic electronic, optical, and transport properties. However, many of their most intriguing phases are metastable—and therefore extremely difficult to synthesize. A prime example is W6Te6, a quasi-1D material predicted to host exotic physics but precluded by the thermodynamically favored growth of the stable WTe2 phase during conventional tellurization of tungsten.
A team of researchers led by Yeliang Wang and Xiaolong Xu from Beijing Institute of Technology has developed a kinetically-controlled anion-exchange (KCAE) strategy that overcomes this fundamental limitation. The two-step process first converts a magnetron-sputtered tungsten film into a stable 2H- WS2 template via sulfurization. This WS2 template exhibits a unique vertically-aligned grain structure, where chemically inert basal planes are minimized and highly reactive layer edges rich in dangling bonds are maximally exposed. In the second step, controlled tellurization replaces sulfur with tellurium through an anion-exchange reaction.
The team published their article in Nano Research on July 4, 2026.
The key to this strategy is the kinetic barrier created by the strong W-S bonds in WS₂. Breaking these bonds requires high activation energy, dramatically slowing the reaction rate compared to the explosive kinetics of direct W-to-WTe2 conversion. This slow, stepwise substitution creates a controllable temporal window that allows isolation of the metastable W6Te6 intermediate before the system reaches the thermodynamic equilibrium state.
Atomic-resolution high-angle annular dark-field scanning transmission electron microscopy directly visualizes the unique quasi-1D chain structure of W6Te6: an inner core of six tungsten atoms surrounded by an outer sheath of six tellurium atoms, with covalently bonded chains stacked via van der Waals forces. Large-area energy-dispersive X-ray mapping confirms uniform distribution of tungsten and tellurium, with quantitative analysis showing a W:Te atomic ratio approaching 1:1, consistent with W6Te6 stoichiometry.
By systematically mapping the synthesis parameter space, the team established a growth phase diagram delineating conditions for unreacted WS2, partial conversion, and phase-pure W6Te6. Guided by this diagram, they synthesized a 1-inch wafer-scale W6Te6 film with uniform Raman signatures across the entire wafer. Furthermore, the two-step template-conversion method is fully compatible with standard photolithography. Pre-patterned tungsten structures were converted sequentially to WS₂ and then to W6Te6, yielding complex patterns with excellent uniformity and structural integrity.
This work provides a scalable and patternable route to the systematic study of W6Te6 and introduces a generalizable platform for the wafer-scale synthesis of metastable van der Waals materials previously inaccessible by conventional methods.
Other contributors include Mingzhu Xu, Mengting Huang, Yiming Ding, Binbin Zhang, Shibo Wang, Wenlei Fu, Huixia Yang, Yu Zhang, Yuanxiao Ma and Ruiwen Shao from Beijing Institute of Technology, Shiqi Yang from Beijing University of Technology, Yu Ye from Peking University.
The authors acknowledge the Analysis & Testing Center, Beijing Institute of Technology for the use of STEM. This work is supported by the National Program for Support of Top-Notch Young Professionals (Grants Nos. 3110013532407, X.X.), the National Key R&D Program of China (Grants Nos. 2023YFB3611700, X.X. and Y.M.), the National Natural Science Foundation of China (Grants Nos. 62274010, X.X.; 92163206, Y.W.; 12321004, Y.W.), Young Elite Scientists Sponsorship Program by CAST (Grants Nos. 2023QNRC001, X.X.), and the open research fund of Suzhou Laboratory (SZLAB-1508-2024-TS014, X.X.).
DOI Link:
https://doi.org/10.26599/NR.2026.94908711
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
