Tunable Band Gap of Boron Nitride Interfaces under Uniaxial Pressure

TL;DR

This study demonstrates that applying uniaxial pressure to hydrogen-terminated boron nitride interfaces can continuously tune their band gap from metallic to insulating, enabling potential applications in electronics and photovoltaics.

Contribution

The paper introduces a method to control the band gap of boron nitride interfaces via uniaxial pressure, revealing a tunable electronic property not previously demonstrated.

Findings

Band gap can be tuned from 0 to 4.4 eV with pressure.

Interface exhibits metallic behavior at contact without pressure.

Potential for high-stability electronic and photovoltaic devices.

Abstract

In this work we show, by means of a density functional theory formalism, that the simple physical contact between hydrogen terminated boron nitride surfaces gives rise to a metallic interface with free carries of opposite sign at each surface. A band gap can be induced by applying uniaxial pressure. The size of the band gap changes continuously from zero up to 4.4 eV with increasing pressure, which is understood in terms of the interaction between surface states. Due to the high thermal conductivity of cubic boron nitride and the coupling between band gap and applied pressure, such tunable band gap interfaces may be used in high stable electronic and electromechanical devices. In addition, the spacial separation of charge carries at the interface may lead to photovoltaic applications.