High thermal conductivity in cubic boron arsenide crystals

Abstract

The high density of heat generated in power electronics and optoelectronic devices is a critical bottleneck in their application. New materials with high thermal conductivity are needed to effectively dissipate heat and thereby enable enhanced performance of power controls, solid-state lighting, communication, and security systems. We report the experimental discovery of high thermal conductivity at room temperature in cubic boron arsenide (BAs) grown through a modified chemical vapor transport technique. The thermal conductivity of BAs, 1000 ± 90 watts per meter per kelvin meter-kelvin, is higher than that of silicon carbide by a factor of 3 and is surpassed only by diamond and the basal-plane value of graphite. This work shows that BAs represents a class of ultrahigh-thermal conductivity materials predicted by a recent theory, and that it may constitute a useful thermal management material for high-power density electronic devices.

Photoluminescence mapping and time-domain thermo-photoluminescence for rapid imaging and measurement of thermal conductivity of boron arsenide

“…Based on well-established relationship between PL and crystal quality and the relationship between crystal quality and thermal conductivity  proved by recent demonstrations and theories 4,5,6,7,8,21 , we speculate that a strong PL must lead to a high . To make use of these relationships for thermal conductivity measurement, we take one step further and utilize confocal PL imaging to evaluate  of large BAs crystals.…”

“…The interest in BAs increased suddenly in 2013 when first-principles calculations predicted BAs as a highly thermal conductive () material with a value comparable to that of diamond and much higher than the most commonly used heat-sink materials like copper and silicon carbide 4,5 . Subsequent intense research led to successful synthesis and verification of the predicted high- material in 2018 by three groups 6,7,8 , which opens up new opportunities for more basic research as well as potential applications as a thermal sink material compatible with silicon 9 . However, despite BAs being first studied in the late 50s of the last century 1 , its actual bandgap value has not been well settled.…”

Basic physical properties of cubic boron arsenide

“…Heat dissipation is a critical technology issue for modern electronics and photonics [1][2][3][4][5] . A key challenge and urgent need for effective thermal management is to discover new materials with ultrahigh thermal conductivity for dissipating heat from hot spots efficiently, and thereby improving device performance and reliability [6][7][8][9][10] . Options to address this challenge with conventional high thermal conductivity materials, such as diamond and cubic boron nitride, are very limited [11][12][13] ; their high cost, slow growth rate, degraded crystal quality, combined with the integration challenge with semiconductors, given chemical inertness and large mismatch in lattice and thermal expansion, make them far from optimal candidates.…”

How to resolve a phonon-associated property into contributions of basic phonon modes

“…Phonons play an important role in many properties of materials, such as thermal conductivity [1][2][3][4][5][6][7], electron/ hole mobility [8][9][10][11][12], thermoelectric efficiency [13,14], superconductivity [15][16][17][18], light adsorption/emission [19][20][21][22], and electron-hole recombination [23,24]. Resolving the phonon-associated property into the contributions of basic phonon/vibration modes is a very useful approach to understand what basic phonon mode(s) govern(s) the property [4, 10-12, 17, 25-27].…”