First-principles quantitative prediction of the lattice thermal conductivity in random semiconductor alloys: The role of force-constant disorder

Article

关键词: ABSORPTION FINE-STRUCTURE;    BOLTZMANN TRANSPORT-EQUATION;    QUASI-RANDOM STRUCTURES;    RANDOM SOLID-SOLUTIONS;    AUGMENTED-WAVE METHOD;    PHONON-SCATTERING;    SYSTEMS;    TEMPERATURES;    GA1-XINXAS;    CRYSTALS;   

DOI  :  10.1103/PhysRevB.98.115205

来源: SCIE

【 摘 要 】

The standard theoretical understanding of the lattice thermal conductivity K-l of semiconductor alloys assumes that mass disorder is the most important source of phonon scattering. In contrast, we find that for the random alloy In1-xGaxAs the hitherto neglected contribution of interatomic force-constant (IFC) disorder is essential for the prediction of K-l. We present an ab initio method based on special quasirandom structures and Green's functions which includes the role of IFC disorder and apply it in order to calculate K-l of In1-xGaxAs and alloys. We show that, while for Si1-xGax, phonon-alloy scattering is dominated by mass disorder, for In1-xGaxAs, the inclusion of IFC disorder is fundamental to reproduce the experimentally observed K-l. We relate this to the underlying atomic-scale structural disorder in In1-xGaxAs. This feature is common to most III-V and II-VI random semiconductor alloys, and we expect the inclusion of IFC disorder in modeling lattice thermal conductivity to be important for a wide class of materials.

【 授权许可】

Free