Effect of doping 3d transition metal (Fe, Co, and Ni) on the electronic, magnetic and optical properties of pentagonal ZnO2 monolayer

The pentagonal ZnO2 (penta-ZnO2) monolayer is a new class of two-dimensional materials with unique properties, which are still largely unknown. This work studies the stability of the geometries, and the modulation of the electronic, magnetic and optical properties of penta-ZnO2 doped with 3d transition metal (TM) (Fe, Co, and Ni) atoms replacing the host Zn atoms by using first-principles calculations. The structural optimization implies that all these three atomic species can be effectively doped in the penta-ZnO2 monolayer, due to the strong hybridization of TM 3d and O 2p states electrons. Furthermore, it is found that the electronic structures and optical properties are tuned by the doping TM atoms. The doping of TM atoms introduces the reduction of the band gap energy, and Fe and Co atoms even endow magnetization to the penta-ZnO2. In addition, the absorption edges of all the three doped systems exhibit an obvious red shift, which can enhance the effective utilization of the solar spectrum in the visible light region. This study gives us an insight in the physical properties of the TM doped penta-ZnO2 monolayer, which could be helpful in realizing their diverse potentials in spintronic and photovoltaic applications.