Band gap engineering via doping: A predictive approach

Abstract

We employ an extension of Harrison's theory at the tight binding level of approximation to develop a predictive approach for band gap engineering involving isovalent doping of wide band gap semiconductors. Our results indicate that reasonably accurate predictions can be achieved at qualitative as well as quantitative levels. The predictive results were checked against ab initio ones obtained at the level of DFT/SGGA + U approximation. The minor disagreements between predicted and ab initio results can be attributed to the electronic processes not incorporated in Harrison's theory. These include processes such as the conduction band anticrossing [Shan et al., Phys. Rev. Lett. 82, 1221 (1999); Walukiewicz et al., Phys. Rev. Lett. 85, 1552 (2000)] and valence band anticrossing [Alberi et al., Phys. Rev. B 77, 073202 (2008); Appl. Phys. Lett. 92, 162105 (2008); Appl. Phys. Lett. 91, 051909 (2007); Phys. Rev. B 75, 045203 (2007)], as well as the multiorbital rehybridization. Another cause of disagreement between the results of our predictive approach and the ab initio ones is shown to be the result of the shift of Fermi energy within the impurity band formed at the edge of the valence band maximum due to rehybridization. The validity of our approach is demonstrated with example applications for the systems GaN1−xSbx, GaP1−xSbx, AlSb1−xPx, AlP1−xSbx, and InP1−xSbx.

Tuning Light‐Driven Water Oxidation Efficiency of Molybdenum‐Doped BiVO4 by Means of Multicomposite Catalysts Containing Nickel, Iron, and Chromium Oxides

“…3.5 eV (see Figure S9), which are the transitions from different states in the BiVO 4 valence band, composed mainly from O 2p and Bi 6s orbitals . As revealed by the Tauc plots for indirect allowed transitions obtained for pristine and catalyst‐modified Mo:BiVO 4 electrodes (Figure ), the incorporation of the catalyst within the Mo:BiVO 4 film did not cause any change of the band gap energy of the photoabsorber, most probably due to the relatively small amounts of dopants . The presence of the catalyst in both configurations significantly increased the surface charge separation efficiency, suggesting a passivation of surface recombination centres for the catalyst deposited on top of Mo:BiVO 4 or a decreased formation of surface recombination centres due to a change in morphology .…”

“…[28] As revealed by the Tauc plots for indirect allowed transitions obtained for pristine and catalyst-modified Mo:BiVO 4 electrodes (Figure 4), the incorporation of the catalyst within the Mo:BiVO 4 film did not cause any change of the band gap energy of the photoabsorber, most probably due to the relatively small amounts of dopants. [29] The presence of the catalyst in both configurations significantly increased the surface charge separation efficiency, suggesting a passivation of surface recombination centres for the catalyst deposited on top of Mo:BiVO 4 or a decreased formation of surface recombination centres due to a change in morphology. [30] This explains the increased photocurrents for the configuration with the catalyst embedded within the Mo: BiVO 4 film, but cannot explain the nearly unchanged photocurrents with the catalyst deposited on top of the Mo:BiVO 4 film.…”

Importance of doping, dopant distribution, and defects on electronic band structure alteration of metal oxide nanoparticles: Implications for reactive oxygen species

“…Recently, notable efforts have been made to achieve theoretical predictability on band structure alteration by dopants and defects (Anderson and Chris, 2009;Andriotis and Menon, 2015); however, continued and systematic research is necessary to evaluate the role of dopant atoms' positioning (surface dopants vs. distributed) (Goings et al, 2014) in band structure modulation as well as its relationship to the ROS-generation-ability of MONPs. Such theoretical development can simplify the job of the nanotoxicology community to narrow down the important MONPs from the large set of ROS-active materials.…”

Methods of photoelectrode characterization with high spatial and temporal resolution

“…Given recent advancements in both high-performance computing and computational algorithms, opportunities for using modeling and simulation as predictive tools for PEC studies are expanding. 17,18,[178][179][180][181] Accordingly, it is becoming increasingly evident that modeling and characterization efforts require tighter integration as PEC research activities move forward. Fig.…”