Background

TMD monolayers are atomically thin semiconductors having direct bandgaps. These monolayers are useful for various types of semiconductors such as photodetectors, optical modulators, solar cells, light-emitting diodes (“LED”), flexible displays, transparent displays, etc. Although there are various useful applications for monolayer and heterostructure TMDs, current chemical vapor deposition methods cannot be used for the growth of large TMDs or over other TMD layers.

Typical current techniques for TMD heterostructure fabrication use a transfer process. According to such a process, each TMD monolayer is grown separately and one monolayer is taken off of the growth substrate and stacked on the other monolayer. However, this transfer process is time-consuming, requires alignment when one monolayer is stacked onto another (which is problematic for some optoelectronics applications), and involves the use of polymers which contaminate the interfaces of resulting TMD heterostructures. While techniques for direct growth of heterostructures exist, such techniques have limitations in terms of their achievable size of heterostructures. Furthermore, only bilayered heterostructures have been demonstrated because such techniques cannot add another layer atop bilayered heterostructures since the materials are either evaporated or damaged during the growth of a subsequent layer.

Summary

A method for growing a transition metal dichalcogenide on a substrate, the method including providing a growth substrate having a first side and a second side opposite the first side; providing a source substrate having a first side and a second side opposite the first side; depositing a transition metal oxide on at least a portion of the first side of the source substrate; combining the growth substrate with the source substrate such that the first side of the growth substrate contacts the transition metal oxide, the combining producing a substrate stack; exposing the substrate stack to a chalcogenide gas, whereby the transition metal oxide reacts with the chalcogenide gas to produce a layer of a transition metal dichalcogenide on at least a portion of the first side of the growth substrate; and removing the source substrate from the growth substrate having the layer of the transition metal dichalcogenide thereon.

Applications:

- VCNT Laser Applications