Searching new semiconductor materials has been vigorously growing for some time, with more sophisticated electronic devices, the demand for semiconductors with diverse range of properties is on the edge. Paving the path for both optical and electronic applications, successful fabrication of nitride is the next cusp as it’s said to emit red light while using high-pressure synthesis.
Fumiyasu Oba and colleagues at Tokyo Institute of Technology and Kyoto University have used calculations to screen a set of compounds for potential semiconductor candidates. The study identified 11 previously unreported materials, including the particularly promising compound calcium zinc nitride (CaZn2N2).
The researchers limit their study to nitrides because they tend to be chemically stable and can be readily made with existing techniques.
Nitrogen is also a widely abundant and environmentally friendly element, but, at present, the nitrides used in industry are largely limited to gallium and indium compounds. Based on similarities in the electronic structure, the researchers rationalised that ternary zinc nitrides would be promising compounds to consider for new semiconductors in this field.
The researchers highlight the previously unreported semiconductor CaZn2N2, which should have a high electrical conductivity and a strong interaction with light. These properties are indicators of good performance in optoelectronic applications such as light emitting diodes (LEDs) and solar cells. It is also made entirely of earth-abundant elements and so can be relatively cheap to make.
Synthesis of the material using high-pressure techniques confirmed the hypothesised properties and also revealed red luminescence even at room temperature; thereby validating the study’s approach.
Until now, Silicon and to a lesser degree germanium are materials ruling the modern electronic market. However, these materials are not apt for optoelectronic applications, such as LEDs for TV or mobile phone screens.
Here, the materials gallium nitride (GaN) and indium nitride (InN) dominate currently, but the discovery of new nitrides could pave the way to new applications.
By using nitrogen and zinc components as criteria for their screening methods, Oba and colleagues are able to maximize the chances of cost competitiveness for their discoveries compared to known materials.
CaZn2N2 has been oblivion previously but with researcher’s discovery, they predict the correct synthesis conditions for CaZn2N2, leading to the successful formation of the new compound using high-pressure synthesis. Further experiments confirmed that the compound has a direct bandgap and favourable optical properties.
The paper states that other earth-abundant materials, such as calcium magnesium nitride, can be used to tune the electrical properties of CaZn2N2, further increasing the eligibility of this material for use in devices.
As Oba and colleagues conclude, “The present study demonstrates accelerated materials discovery via cutting-edge computational screening followed by targeted experiments.”