Correlation between the ionicity, Debye temperature, cohesive energy and thermal expansion coefficient of the group IIB-VIA semiconductors

Abstract Based on the local bond average approach and the definition of the thermal expansion coefficient, the temperature-dependent thermal expansion coefficient for Group ⅡB-ⅥA semiconductors has been established. The consistency in theoretical results and reported values confirms that the higher the Debye temperature, the wider the nonlinear range of the thermal expansion coefficient at low temperatures, and the lower the change rate for the temperature-dependent thermal expansion coefficient. The bigger the ionicity, the shorter the bond length, and the smaller the thermal expansion coefficient. The influence of ionicity on the thermal expansion coefficient is greater than those of both Debye temperature and cohesive energy. The present analytical function is beyond the scope of available approaches, which not only provides a new understanding of the physical mechanism of the thermal expansion coefficient response to temperature but also is helpful in the quantitative design of semiconducting optoelectronic devices.