The binary nitride semiconductors gallium nitride, indium nitride and aluminum nitride and their alloys have found important commercial applications in optoelectronics and high-power electronics, but indium and gallium are expensive and scarce, and flexibility in the design and control of the properties of devices based upon mixtures of just these three compounds is limited. There is growing interest in the much larger, but much less well-studied, family of ternary nitride semiconductors that include, for example, zinc germanium nitride and zinc tin nitride, formed by replacing the group III binary element with equal proportions of group II and group IV elements. Many of these dozens of potentially useful materials are composed entirely of earth-abundant, inexpensive, and benign elements. The increased complexity of the ternary nitrides, and the greater number of materials and combinations, is expected to lead to new materials properties and more flexibility in their design. This project will accelerate research on this new family of materials by combining efforts in theoretical calculations and modeling of devices and properties with synthesis and characterization focused on an important subset of these materials. Dissemination of new and archived results via an interactive website-accessed database available freely to the community will foster a growing network among research groups that will accelerate progress toward understanding and controlling the properties of these materials and developing new applications for them.
research will focus on developing growth and doping methods for ZnGeN2 and ZnGeN2-GaN mixed ternary-binary heterostructures by metalorganic chemical vapor deposition (MOCVD). This focus will take strategic advantage of the mature technology for GaN growth and doping, earlier demonstrations of successful growth of ZnGeN2 by MOCVD, the close lattice mismatch of the two materials, and their close optimized growth conditions. The focus additionally will take advantage of the theoretically predicted large band offset between the two materials, which have similar band gaps in the near-ultraviolet, in the design and synthesis of the interesting heterostructure and alloy systems that result from this situation. The theoretical and experimental results, combined with the development of a network, based upon the publicly accessible database website for research groups working in this area, will lay the foundation for expanding research efforts on this large family of materials.
