Two-dimensional solid-phase crystallization toward centimeter-scale monocrystalline layered MoTe 2 via two-step annealing

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 9; no. 43; pp. 15566 - 15576
• Main Authors: Lin, Chih-Pin, Hsu, Hao-Hua, Huang, Jyun-Hong, Kang, Yu-Wei, Wu, Chien-Ting, Lee, Yao-Jen, Cheng, Chun-Cheng, Lan, Yann-Wen, Chang, Wen-Hao, Li, Lain-Jong, Hou, Tuo-Hung
• Format: Journal Article
• Language: English
• Published: 11.11.2021
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/D1TC03123F

The lack of effective synthesis techniques for achieving wafer-scale uniformity and high crystallinity remains one of the major obstacles for two-dimensional (2D) layered materials in practical applications. 2D solid-phase crystallization (2DSPC) is proposed based on the area-scalable and semiconductor-process-compatible sputtering and thermal annealing techniques. It successfully synthesizes few-layer 2H-MoTe 2 with a monocrystalline grain size exceeding half a centimeter on an amorphous substrate of silicon dioxide. The extremely large grain size is made possible through a two-step annealing process in an inert atmosphere. The initial rapid thermal annealing at high temperatures produces hexagonal monocrystalline 2H-MoTe 2 seeds with low density and the subsequent long-duration furnace annealing at low temperatures enlarges the monocrystalline domains only from the pre-existing seeds. The 2DSPC mechanism and its morphological evolution agree with the classical nucleation theory and kinetic Wulff construction theory, respectively. Our result suggests the promising potential of 2DSPC as a simple yet effective route for synthesizing future wafer-scale, high-quality 2D materials.