First-Principles Studies for Electronic Structure and Optical Properties of Strontium Doped β-Ga2O3

Micromachines

MohdHazrie Samat¹  MohamadFariz Mohamad Taib¹  DillaDuryha Berhanuddin²  Raihana Bahru²  MohdAmbri Mohamed²  Abhay Kumar Mondal²  Loh Kean Ping²  P.Susthitha Menon² 

[1] Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Shah Alam 40450, Selangor, Malaysia;Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Selangor, Malaysia;

关键词: first-principles;    density functional theory;    pure β-Ga₂O₃;    Sr-doped β-Ga₂O₃;    p-type doping;    band structure;   

DOI  :  10.3390/mi12040348

来源: DOAJ

【 摘 要 】

The crystal structure, electron charge density, band structure, density of states, and optical properties of pure and strontium (Sr)-doped β-Ga₂O₃ were studied using the first-principles calculation based on the density functional theory (DFT) within the generalized-gradient approximation (GGA) with the Perdew–Burke–Ernzerhof (PBE). The reason for choosing strontium as a dopant is due to its p-type doping behavior, which is expected to boost the material’s electrical and optical properties and maximize the devices’ efficiency. The structural parameter for pure β-Ga₂O₃ crystal structure is in the monoclinic space group (C2/m), which shows good agreement with the previous studies from experimental work. Bandgap energy from both pure and Sr-doped β-Ga₂O₃ is lower than the experimental bandgap value due to the limitation of DFT, which will ignore the calculation of exchange-correlation potential. To counterbalance the current incompatibilities, the better way to complete the theoretical calculations is to refine the theoretical predictions using the scissor operator’s working principle, according to literature published in the past and present. Therefore, the scissor operator was used to overcome the limitation of DFT. The density of states (DOS) shows the hybridization state of Ga 3d, O 2p, and Sr 5s orbital. The bonding population analysis exhibits the bonding characteristics for both pure and Sr-doped β-Ga₂O₃. The calculated optical properties for the absorption coefficient in Sr doping causes red-shift of the absorption spectrum, thus, strengthening visible light absorption. The reflectivity, refractive index, dielectric function, and loss function were obtained to understand further this novel work on Sr-doped β-Ga₂O₃ from the first-principles calculation.

【 授权许可】

Unknown