Synthesis of CaSnN2 via a High-Pressure Metathesis Reaction and the Properties of II-Sn-N2 (II = Ca, Mg, Zn) Semiconductors

A novel ternary nitride semiconductor, CaSnN2, with a layered rock-salt-type structure (R (3) over barm) was synthesized via a high-pressure metathesis reaction. The properties and structures of II-Sn-N-2 (II = Ca, Mg, Zn) semiconductors were also systematically studied, and the differences among them were revealed by comparison. These semiconductor materials showed a rock-salt- or wurtzite-type structure depending on the combined effect of the synthetic conditions and the characteristics of the group II elements. Additionally, the rock-salt-type structures of CaSnN2 and MgSnN2 (i.e., the ambient-pressure phase) were different from those predicted using first-principles calculations. Further, on the basis of first-principles calculations and consideration of the pressure effect, the recovered CaSnN2 sample showed an R (3) over barm structure. CaSnN2 and MgSnN2 showed a band gap of 2.3-2.4 eV, which is suitable for overcoming the green-light-gap problem. These semiconductors also showed a strong cathode luminescence peak at room temperature, and generalized gradient approximation (GGA) calculations revealed that CaSnN2 has a direct band gap. These inexpensive and nontoxic semiconductors (II-Sn-N-2 semiconductors (II = Ca, Mg, Zn)), with mid band gaps are required as pigments to replace cadmium-based materials. They can also be used in emitting devices and as photovoltaic absorbers, replacing InxGa1-xN semiconductors.

Automated summary

A novel ternary nitride semiconductor CaSnN2 with a rock-salt-type structure was synthesized, along with the systematic study of II-Sn-N-2 (II = Ca, Mg, Zn) semiconductors. Differences in structure and properties were revealed, showing CaSnN2 and MgSnN2 have band gaps suitable for various applications. These inexpensive and nontoxic semiconductors have potential as replacements for cadmium-based materials in pigments, as well as for InxGa1-xN semiconductors in emitting devices and photovoltaic absorbers.