Boron isotope effect on the thermal conductivity of boron arsenide single crystals

TL;DR

This study investigates how boron isotopic composition affects the ultrahigh thermal conductivity of boron arsenide single crystals, revealing that isotopically pure BAs has at least 10% higher thermal conductivity than natural B.

Contribution

It provides detailed growth methods for BAs with different isotopic ratios and demonstrates the impact of isotopic purity on thermal conductivity, advancing understanding of isotope effects in high thermal conductivity materials.

Findings

Isotopically pure BAs has at least 10% higher thermal conductivity than natural B.

Raman spectroscopy shows differences in phonon scattering among BAs samples.

Guidelines for isotope optimization to enhance thermal conductivity in BAs.

Abstract

Boron arsenide (BAs) with a zinc blende structure has recently been discovered to exhibit unusual and ultrahigh thermal conductivity (k), providing a new outlook for research on BAs and other high thermal conductivity materials. Technology for BAs crystal growth has been continuously improving, however, the influence of boron isotopes, pure or mixed, on the thermal conductivity in BAs is still not completely clear. Here we report detailed studies on the growth of single crystals of BAs with different isotopic ratios and demonstrate that the k of isotopically pure BAs is at least 10% higher than that of BAs grown from natural B. Raman spectroscopy characterization shows differences in scattering among various BAs samples. The presented results will be helpful in guiding further studies on the influence of isotopes on optimizing k in BAs.