First-principles study of strain effects on Zn vacancies and H-interstitial ZnO(001) monolayers: Mg-induced photovoltaic and antiferromagnetic behaviour

The identification of photovoltaic infrared effect materials is pivotal for realising highly efficient thermophotovoltaic devices. Secondly, this study aims to resolve the ferromagnetic properties erroneously reported in prior research [International Journal of Hydrogen Energy 60 (2024) 402–414] by demonstrating the antiferromagnetic nature of the Zn 34 H i MgO 36 (0 0 1) monolayer system under unstrained neutral conditions. Employing the Generalised Gradient Approximation (GGA + U) plane-wave super-soft pseudopotential within the spin density functional theory framework, this study investigates the influence of strain on the thermophotovoltaic response of Zn-vacancy and H-interstitial ZnO(0 0 1) monolayers: Mg. Dynamic analysis, quantum mechanical minimum energy principle, and differential charge density distribution studies indicate that the Zn 34 H i MgO 36 (0 0 1) monolayer system exhibits relatively good stability under −6% compressive strain. Spin density, Bader charge, and density of states distribution investigations reveal that both unstrained and tensile/compressive strains induce antiferromagnetism in the Zn 34 H i MgO 36 (0 0 1) monolayer system exhibits antiferromagnetism regardless of strain state. The antiferromagnetic mechanism originates from the polarised O 1- 1 2p state ions near Zn vacancies and O 1- 2 2p states, both possessing dual attributes of localised electrons (acceptors) and itinerant electrons (donors). Hybridised double exchange interactions exist between these localised electrons. Trapping effects and carrier lifetime studies reveal that the Zn 34 H i MgO 36 (0 0 1) monolayer system under −6% compressive strain exhibits the longest carrier lifetime. Absorption coefficient and reflectance coefficient investigations indicate that the Zn 34 H i MgO 36 (0 0 1) monolayer system under −6% compressive strain demonstrates the most favourable infrared photovoltaic properties as a thermophotovoltaic material.