Half-Heusler Semiconductors as Piezoelectrics

We use a first-principles rational-design approach to demonstrate the potential of semiconducting half-Heusler compounds as a previously unrecognized class of piezoelectric materials. We perform a high-throughput scan of a large number of compounds, testing for insulating character and calculating structural, dielectric, and piezoelectric properties. Our results provide guidance for the experimental realization and characterization of high-performance materials in this class that may be suitable for practical applications.

Figure 1

The $ABC$ half-Heusler structure: $A$ (green, big circles) and $B$ (orange, small circles) are arranged in a rocksalt lattice, with the tetrahedral coordination of $C$ (blue, biggest circles) by $A$ shown.

Figure 2

(a) Cell parameters (in Å) of insulating $ABC$ combinations as well as their range of band gaps (in eV) are depicted as black circles. (b) Electromechanical coupling factor $k_{14}$ of insulating $ABC$ combinations as a function of piezoelectric constant $e_{14}$. Known combinations, from Table , are highlighted as (bigger) filled red circles.