# van der Waals Nanochemical Reactors

## TL;DR

Scientists use van der Waals stacks as nanochemical reactors to synthesize high-quality single crystals of materials like tellurium and Pd–Te compounds.

## Contribution

Introduces van der Waals stacks as a generalizable and chip-integrable method for nanoconfined single-crystal synthesis.

## Key findings

- Synthesized isolated single crystals of elemental tellurium and Pd–Te compounds with high crystalline quality.
- Observed intrinsic semiconducting properties in tellurium and superconductivity in nonstoichiometric PdTe1–x.
- vdW nanoreactors are compatible with nanofabrication and suitable for a wide range of processing conditions.

## Abstract

Synthesizing single crystals suitable for quantum electronic
discoveries
remains challenging for many emerging materials. We introduce van
der Waals (vdW) stacks as nanochemical reactors for single-crystal
synthesis and demonstrate their broad applicability in growing both
elemental and compound crystals at the micrometer scale. By encapsulating
atomically thin reactants that are stacked compactly with inert vdW
layers, we achieve nanoconfined synthesis with the resulting crystals
remaining encapsulated. As a proof of concept, we synthesized isolated
single crystals of elemental tellurium and distinct types of Pd–Te
compounds. Structural characterization confirms the high crystalline
quality of the products. We observe the intrinsic semiconducting gap
of tellurium and superconductivity in nonstoichiometric PdTe1–x
with a significantly reduced Te content. The concept
of vdW nanoreactors is broadly generalizable, chip-integrable, well-suited
to a wide range of processing conditions, and compatible with nanofabrication,
offering a versatile pathway to expand the accessible landscape of
quantum materials.