Besides controlling reaction pathways relevant to electrocatalysis, chemically structured interfaces can also mediate key intermediates during crystal growth. We recently demonstrated that Si(001) substrates treated with low partial pressures of phosphine produce a synthetic surface with a distribution of Si–P dimers and P–P dimers. These synthetic surfaces catalyze and substantially alter the growth of 2D transition metal dichalcogenide (TMD) crystals yielding materials with tailored dimensionality, morphology and atomically precise edges. Such control provides the opportunity to tune the electronic, magnetic, optical, and catalytic properties of these materials with great precision. Indeed, the resulting TMD crystals exhibit intriguing optical anomalies including an edge- and strain-mediated photoluminescence that is localized and significantly red-shifted in energy. This talk will focus on our recent insights into the mechanism by which these synthetic surfaces alter the nucleation and growth of 2D crystals. Our results identify subtle but important shifts in the composition and heterogeneity of the surface as a function of phosphine partial pressure. The complex chemical landscape of the surface in turn defines the interface energetics that determine the crystal geometry, morphology, and phase. These and our continuing efforts highlight the importance of rational chemical design of low-dimensional materials that can enable future energy conversion and quantum device goals.

Catalyzing and tailoring the growth of 2D materials at chemically structured interfaces

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.