One-dimensional Si chains embedded in Pt(111)and protected by a hexagonal boron-nitride monolayer

TL;DR

This study demonstrates the formation of one-dimensional silicon chains on Pt(111) surfaces, their vulnerability to residual gases, and how a hexagonal boron nitride monolayer can stabilize and protect these chains from environmental degradation.

Contribution

It introduces a method to stabilize silicon chains on Pt(111) using a boron nitride monolayer, enabling their preservation in ambient conditions.

Findings

Silicon chains form on Pt(111) at 300K and are oriented along <112>-direction.

Residual gases, especially CO, cause the chains to disappear over time.

A hexagonal boron nitride monolayer stabilizes the chains, allowing them to survive air exposure.

Abstract

Using scanning tunneling microscopy, we show that Si deposition on Pt(111) at 300K leads to a network of one-dimensional Si chains. On the bare Pt(111) surface, the chains, embedded into the Pt surface, are orientated along the <112>-direction. They disappear within a few hours in ultrahigh vacuum due to the presence of residual gas. Exposing the chains to different gases deliberately reveals that CO is largely responsible for the disappearance of the chains. The chains can be stabilized by a monolayer of hexagonal boron nitride, which is deposited prior to the Si deposition. The resulting Si chains are rotated by 30{\deg} with respect to the chains on the bare Pt(111) surface and survive even an exposure to air for 10 minutes.