Electronic Properties of ZnVNbN Alloys to Model Novel Materials for Light-Emitting Diodes.
Ana-Maria Stratulat, Christian Tantardini, Maryam Azizi, Tariq Altalhi, Sergey V Levchenko, Boris I Yakobson
Author Information
Ana-Maria Stratulat: Skolkovo Innovation Center, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Moscow 143026, Russian Federation.
Christian Tantardini: Hylleraas Center, Department of Chemistry, UiT The Arctic University of Norway, PO Box 6050 Langnes, N-9037 Tromsø, Norway. ORCID
Maryam Azizi: Université Catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-Neuve, Belgium.
Tariq Altalhi: Chemistry Department, Taif University, Al Hawiyah, Taif 26571, Saudi Arabia.
Sergey V Levchenko: Skolkovo Innovation Center, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Moscow 143026, Russian Federation.
Boris I Yakobson: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States. ORCID
We propose the ZnVNbN alloy as a new promising material for optoelectronic applications, in particular for light-emitting diodes (LEDs). We perform accurate electronic-structure calculations of the alloy for several concentrations using density-functional theory with meta-GGA exchange-correlation functional TB09. The band gap is found to vary between 2.2 and 2.9 eV with varying V/Nb concentration. This range is suitable for developing bright LEDs with tunable band gap as potential replacements for the more expensive GaInN systems. Effects of configurational disorder are taken into account by explicitly considering all possible distributions of the metal ions within the metal sublattice for the chosen supercells. We have evaluated the band gap's nonlinear behavior (bowing) with variation of V/Nb concentration for two possible scenarios: (i) only the structure with the lowest total energy is present at each concentration and (ii) the structure with minimum band gap is present at each concentration, which corresponds to experimental conditions when also metastable structures are presents. We found that the bowing is about twice larger in the latter case. However, in both cases, the bowing parameter is found to be lower than 1 eV, which is about twice smaller than that in the widely used GaInN alloy. Furthermore, we found that both crystal volume changes due to alloying and local effects (atomic relaxation and the V-N/Nb-N bonding difference) have important contributions to the band gap bowing in ZnVNbN.
References
Phys Rev Lett. 2010 Jun 11;104(23):236403
[PMID: 20867256]
Sci Technol Adv Mater. 2015 Mar 17;16(2):024902
[PMID: 27877769]
