Abnormal physics of group-II telluride system: valence contribution of d electrons

The physical trend of group-II tellurides is unexpected and contrary to the conventional wisdom. The present first-principles calculations give fundamental insights into the extent to which group-II telluride compounds present special properties upon mixing the d valence character. Our results provide explanations for the unexpected experimental observations based on the abnormal binding ordering of metal d electrons and their strong perturbation to the band edge states. The insights into the binary tellurides are useful for the study and control of the structural and chemical perturbation in their ternary alloys and heterostructures.