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

Abstract

Cubic boron arsenide (BAs) is attracting greater attention due to the recent experimental demonstration of ultrahigh thermal conductivity \k{appa} above 1000 W/mK. However, its bandgap has not been settled and a simple yet effective method to probe its crystal quality is missing. Furthermore, traditional \k{appa} measurement methods are destructive and time consuming, thus they cannot meet the urgent demand for fast screening of high \k{appa} materials. After we experimentally established 1.82 eV as the indirect bandgap of BAs and observed room-temperature band-edge photoluminescence, we developed two new optical techniques that can provide rapid and non-destructive characterization of \k{appa} with little sample preparation: photoluminescence mapping (PL-mapping) and time-domain thermo-photoluminescence (TDTP). PL-mapping provides nearly real-time image of crystal quality and \k{appa} over mm-sized crystal surfaces; while TDTP allows us to pick up any spot on the sample surface and measure its \k{appa} using nanosecond laser pulses. These new techniques reveal that the apparent single crystals are not only non-uniform in \k{appa}, but also are made of domains of very distinct \k{appa}. Because PL-mapping and TDTP are based on the band-edge PL and its dependence on temperature, they can be applied to other semiconductors, thus paving the way for rapid identification and development of high-\k{appa} semiconducting materials.

References in corpus (7)

• Measurement Techniques for Thermal Conductivity and Interfacial Thermal Conductance of Bulk and Thin Film Materials
• Tutorial: Time-domain thermoreflectance (TDTR) for thermal property characterization of bulk and thin film materials
• BAs and boride III-V alloys
• Band structure and carrier effective masses of boron arsenide: effects of quasiparticle and spin-orbit coupling corrections
• Point defects and dopants of boron arsenide from first-principles calculations: donor compensation and doping asymmetry
• Boron isotope effect on the thermal conductivity of boron arsenide single crystals
• Effect of nucleation sites on the growth and quality of single-crystal boron arsenide

Cited by in corpus (4)

• Idealizing Tauc Plot for Accurate Bandgap Determination of Semiconductor with UV-Vis: A Case Study for Cubic Boron Arsenide
• Optical properties of cubic boron arsenide
• Invariant expansion of the 30-band k.p model and its parameters for III-V compounds
• Strong Temperature Dependence of Thermal Conductivity in High-Purity Cubic Boron Arsenide