Versatile and scalable chemical vapor deposition of vertically aligned MoTe2 on reusable Mo foils

Layered MoTe2 has shown great promises for optoelectronics and energy-storage applications due to its exceptional optical and electrochemical properties. To date, considerable efforts have been devoted to fabricating layered MoTe2 with lateral orientation by means of mechanical/chemical exfoliation and chemical vapor deposition (CVD) methods. As compared to its horizontal counterparts, vertically aligned MoTe2 with higher density of active edge sites is expected to possess unique optoelectronic and electrochemical properties, while which has not been reported yet. In this work, we report a versatile and scalable CVD growth of vertically aligned MoTe2 with length of up to ∼ 7.5 µm on Mo foil. Remarkably, the dominant phase of the vertically aligned MoTe2 can be tuned from 2H to 1T’ by increasing the growth temperature from 630 to 780 °C. Owing to the weak interaction between the as-grown MoTe2 and Mo foil, the as-grown MoTe2 can be easily detached from the Mo foil. This in turn enabled economic reuse of the Mo foil for multiple growth. Moreover, the vertical growth of the MoTe2 is proposed to be caused by the internal strain generated during tellurization of Mo foil. Furthermore, the as-grown MoTe2 can also be directly dispersed in solvent to produce high-quality MoTe2 nanosheets. The versatility of this growth strategy was further demonstrated by fabricating other vertically aligned TMDs such as TaTe2 and MoSe2. Hence, this work paves the path towards achieving unique TMDs structures to enable high-performance optoelectronic and electrochemical devices.