Phonon resonance scattering caused by point defects has long been believed to be able to induce an abnormal temperature dependence of thermal conductivity κ that significantly deviates from the prediction of Rayleigh scattering. However, a rigorous demonstration and microscopic origin of this behavior are still lacking. Here, using an ab initio Green's function approach, we show that three types of point defects cause phonon resonance scattering in cubic BN, among which only the nitrogen vacancy indeed produces an unusual nonmonotonic temperature dependence of κ. This abnormal behavior arises only when the phonon resonance is sufficiently strong and occurs at relatively low phonon frequencies, which overwhelms the intrinsic scattering of low-frequency phonons that otherwise would produce a monotonic temperature dependence of κ. Our work provides deep insights into the phonon resonance caused by point defects and will benefit the manipulation of κ by defect engineering, particularly for doping scenarios.

Close

PrevNext

View figure in article

• Defects
• Phonons
• Thermal conductivity
• Green's function methods