Abstract
Cadmium based Zintl phase compounds have been recently studied for the thermoelectric applications. Many interesting experimental results reported on the 1-2-2 cadmium based compounds, however less attention been paid to study them though first principles methods. In the current work, BaCd2X2 (X= P, As, As, Bi) compounds have been studied comprehensively for the basic structural parameters, electronic band profiles, optical characteristics and thermoelectric properties. Poirier–Tarantola equation of state is used to fit the volume and energy data. The calculated results are consistent with the reported experimental results. Electronic band profiles of the compounds reveal that the compounds are semiconductors except BaCd2Bi2 which is metallic. Valence band is composed on mainly X-p states while Ba-d state in conduction band. Compounds show prominent absorption in the visible region with extension to low frequency ultraviolet region. The characteristics optical peaks redshifted by anion replacement from P to Bi. Thermoelectric properties of the compounds are also studied for possible thermoelectric applications.
The thermal conductivity of the BaCd2X2 (X= P, As, As, Bi) (a) electric part (b) phononic part. With the increase of temperature electrical part of thermal conductivity increased while phononic part of thermal conductivity decreased. [Display omitted]