New Family of Anisotropic Zinc-Based Semiconductors in a Shallow Energy Landscape

The grand challenge of synthesizing materials by predictive design remains outstanding because controlling all necessary thermodynamic and kinetic factors quickly becomes intractable, even for well-known systems. Nevertheless, predictions that are strengthened by large amounts of quality data should have well-defined rates of success. Here, we show that density functional theory calculations highlight four chemical landscapes in alkali-zinc-chalcogenide ternary systems that appear to be densely populated by new phases. For such 3d¹⁰ systems, the total energy calculations are so accurate that a majority of the newly predicted ground-state phases are synthesized experimentally. Nine new ternary phases are presented, compared to the two that were previously known. The compounds Na₂Zn₂S₃, Na₆ZnSe₄, Na₂ZnSe₂, Na₂Zn₂Se₃, K₆ZnS₄, K₂ZnS₂, K₂Zn₃S₄, K₂ZnSe₂, and K₂Zn₃Se₄ are all semiconductors with Zn-S connectivity ranging from zero-to two-dimensional. Their anisotropic structures lead to potential applications in birefringence and UV absorption. Even for relatively common combinations of elements, the potential for computationally informed material discovery remains high.