Theoretical Investigations on the n-Type and p-Type Conductivity Mechanisms in BiTaO Photocatalysts through Intrinsic Point Defects and Group IIA and Group VIB Element Doping.

The n-type and p-type conductivity mechanisms from intrinsic defects and Group IIA and Group VIB element doping in the photocatalyst BiTaO are systematically investigated by employing hybrid density functional calculations. The results reveal that vacancies , , , and antisite Ta are the predominant defects, depending on growth conditions. Bi-rich, appropriate Ta-rich, and O-poor conditions can promote BiTaO to form n-type conductivity due to the presence of the Ta donor defect and its easier ionization.

From K[ZnBPO] to K[(ZnAl)PO]: Substitution-Induced Microporous Zincoaluminophosphate with a Congruent-Melting Behavior.

An open-frame aluminophosphate, K[(ZnAl)PO] (KZAPO), was rationally designed by a substitution design strategy and synthesized by a high-temperature molten salt method. Compared with the parent crystal of K[ZnBPO], KZAPO was characterized by similar 4 × 8 × 8 networks, a comparable short-wave ultraviolet transparency and a more regular tetrahedral frame with the mixing of (ZnO) and (AlO) anionic groups, highlighting the multifunctional roles that anionic group mixing played in structural and property modulations. In particular, KZAPO was characterized by a high thermal stability (over 850 °C) and a congruent-melting behavior, being conducive to practical applications.

Hybrid density functional studies of native defects and H impurities in wurtzite CdSe.

In this study, the formation energies and electronic properties of six native defects as well as H impurities in wurtzite (wz) CdSe are systematically investigated using hybrid density functional calculations. It is shown that native defects, including antisite Cd and interstitial Cd, may be sources of the unintentional n-type conductivity in CdSe under Se-poor conditions; meanwhile, the vacancy defect V is not a good donor. However, when the common H impurity is considered, it is suggested that both the substitutional impurity H and the interstitial impurity H are the dominant and effective origins of the unintentional n-type conductivity in Se-poor conditions.

Cold atom-atom-anion three-body recombination of HeHeLi (x = 6 or 7) systems.

Atom-atom-anion three-body recombination (TBR) in mixed He and Li (x = 6 or 7) is investigated in the adiabatic hyperspherical representation by quantum mechanically solving the Schrödinger equation. The distributions of product states following these TBR processes are found to be relatively different for the two systems when the collision energy is less than roughly 0.6 mK × k or 0.