First principles calculations and analysis of electronic and optical structure of Ho-doped ZnO films
In this study First Principles calculations were carried out in order to analyze the effects of Ho-doping rate on the electronic and optical properties of ZnO films. The band structure, optical properties and density of states of Ho-doped ZnO with the doping rates of 0%, 1.38%, 1.85%, 2.78%, 4.17%, 6.25%, 12.5% and 25% were calculated and compared with our previous experimental results. XRD graphs showed that the Ho-doped ZnO had hexagonal structure with (101) preferential orientation. The optical band gap value for undoped ZnO firstly decreases to 3.055 eV for 1.38% Ho content, then starts to increase to the values of 3.109 eV and 3.177 eV for 1.85% and 2.77% Ho-ratios. Band gap decreases to 2.999 eV with 4% Ho-doping ratio again like the decrease in 1.38% Ho-content. Its observed that bandgap decreases with the decrease in a and b supercell parameters, the bandgap increases with the decrease on c supercell parameter, to verify that the %6.25, %12.5 and %25 doping rates are also studied and the bandgap kept increasing to 3.071 eV for %6.25 Ho-doping rate, 3.147 eV for %12.5 Ho-doping rate. The last calculation for %25 Ho-doping rate showed that the bandgap decreased to 2.727 eV. The optical calculations revealed that Ho-doping leds to blue shift and red shifts in optical absorption, transmittance, dielectric function, reflectivity, refractive index, extinction coefficient, optical conductivity, and loss function characterizations. Result shows that ZnO can be healed by Ho-doping and the calculations carried out by First principles are in a good harmony with experimental results.
- Dergi
- JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
- Yıl
- 2023
- Cilt
- 34
- Sayı
- 8
- ISSN
- 0957-4522
- eISSN
- 1573-482X
- DOI
- 10.1007/s10854-023-10168-5
- WoS UID
- WOS:000953576000006