Study of Native Defects and Transition-Metal (Mn, Fe, Co, and Ni) Doping in a Zinc-Blende CdS Photocatalyst by DFT and Hybrid DFT Calculations

Abstract

We use first-principles DFT and hybrid DFT calculations to investigate the formation of native defects and transition-metal (Mn, Fe, Co, and Ni) doping in zinc-blende CdS and their effect on the electronic structures. Our results reveal that Cd vacancies, S vacancies, interstitial Cd, and interstitial S are dominant native defects, in good agreement with experimental results. Except interstitial S, other native defects do not contribute to visible light absorption. Transitionmetal dopants tend to substitute a lattice Cd atom under S-rich conditions and occupy a tetrahedral interstitial site under p-type and Cd-rich conditions. The doping becomes difficult with increasing the atomic number of the transition metal. Co doping does not contribute to visible light absorption. Mn, Fe, and Ni doping, especially interstitial Ni doping, is able to narrow the band gap, and thus, these transition metals are good dopant candidates to tailor the visible light absorption property of nanosized CdS photocatalysts.

Degradation of Cd-yellow paints: Ab initio study of native defects in {10.0} surface CdS

“…Under Cd-rich growth conditions the general situation follows the opposite trend. Consistently with our results, Wu et al [33] calculated for CdS in zincblende phase formation energies of Cd and S vacancies obtaining 4.15 and 1.33 eV, respectively.…”

Illustration of high-active Ag2CrO4 photocatalyst from the first-principle calculation of electronic structures and carrier effective mass

“…From the thermodynamic viewpoint, the reduction potential of electron acceptors should be energetically below the CB bottom of a semiconductor, and oxidization potential level of electron donors should be above the VB top [36]. Furthermore, the band gap size is also important, as it determines the light absorption range of semiconductor and the number of photo-generated electron-hole pairs [37]. In order to more use visible light in solar spectrum, the band gap of semiconductors should be smaller than 3.1 eV ( c > 400 nm).…”

Construction of Shallow Surface States through Light Ni Doping for High‐Efficiency Photocatalytic Hydrogen Production of CdS Nanocrystals

“…Hybrid DFT calculations demonstrated that substitutional Ni doping can form electron states about 0.24 eV below the conduction band. [26] Therefore, Nidoped CdS-NWS (Ni-CdS-NWS) were fabricated by using this strategy. SPV spectroscopy, TPV measurements, and PL spectroscopy were applied to study the dynamic properties of photogenerated charge carriers trapped by different surface states.…”