Enhanced van der Waals epitaxy via electron transfer-enabled interfacial dative bond formation

TL;DR

This paper demonstrates that electron transfer can activate dative bond formation at the interface of vdW materials, significantly enhancing epitaxy quality, as shown by first-principles calculations of CdTe on NbSe2.

Contribution

It reveals a new mechanism for enhanced vdW epitaxy through electron transfer-induced dative bonds, expanding understanding of interfacial chemistry in layered materials.

Findings

Bond strength at CdTe-NbSe2 interface is five times larger than at CdTe-graphene.

Electron transfer from Cd to NbSe2 activates dative bond formation.

Enhanced binding improves epitaxial growth quality.

Abstract

Enhanced van der Waals (vdW) epitaxy of semiconductors on layered vdW substrate is identified as the formation of dative bonds. For example, despite that NbSe2 is a vdW layered material, first-principles calculations reveal that the bond strength at CdTe-NbSe2 interface is five times as large as that of vdW interaction at CdTe-graphene interface. The unconventional chemistry here is enabled by an effective net electron transfer from Cd dangling-bond states at CdTe surface to metallic non-bonding NbSe2 states, which is a necessary condition to activate the Cd for enhanced binding with Se.