TY - JOUR

T1 - Impact of lanthanum doping on the electronic structure of oxygen vacancies in hafnium oxide

AU - Perevalov, Timofey V.

AU - Islamov, Damir R.

N1 - This work was supported by the Russian Science Foundation, grant № 22-22-00634. The ab initio simulations were carried out at the NSU Supercomputer Center.

PY - 2024/1/30

Y1 - 2024/1/30

N2 - The electronic structure of oxygen vacancies in lanthanum-doped hafnium oxide (HfO2:La) is studied using the density functional theory. The simulation is carried out for the optimal structure of HfO2:La in three crystalline phases for an oxygen vacancy involved in the impurity charge compensation that is structural element, as well as for a second purposely added oxygen vacancy. It is shown that the HfO2 doping with La increases the oxygen vacancy content in such a way that the twice positively charged vacancy concentration increases and the neutral one decreases. The doping with La facilitates new oxygen vacancies formation in HfO2. Oxygen vacancies in HfO2:La and HfO2 have a similar electronic structure and are traps for electrons. However, the deeper trap and the electrostatic repulsion caused by the impurity in HfO2:La suppress the vacancies participation in the charge transport. Based on the obtained results, the mechanisms of HfO2-based resistive and ferroelectric memory improvements, when HfO2 doped with lanthanum, are discussed.

AB - The electronic structure of oxygen vacancies in lanthanum-doped hafnium oxide (HfO2:La) is studied using the density functional theory. The simulation is carried out for the optimal structure of HfO2:La in three crystalline phases for an oxygen vacancy involved in the impurity charge compensation that is structural element, as well as for a second purposely added oxygen vacancy. It is shown that the HfO2 doping with La increases the oxygen vacancy content in such a way that the twice positively charged vacancy concentration increases and the neutral one decreases. The doping with La facilitates new oxygen vacancies formation in HfO2. Oxygen vacancies in HfO2:La and HfO2 have a similar electronic structure and are traps for electrons. However, the deeper trap and the electrostatic repulsion caused by the impurity in HfO2:La suppress the vacancies participation in the charge transport. Based on the obtained results, the mechanisms of HfO2-based resistive and ferroelectric memory improvements, when HfO2 doped with lanthanum, are discussed.

KW - Crystalline oxides

KW - Density functional theory

KW - Electrical conductivity

KW - Electronic structure

KW - Vacancies

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85179135589&origin=inward&txGid=b20649c1f797eade3aa3af1a16b4004d

UR - https://www.webofscience.com/wos/woscc/full-record/WOS:001135545100001

UR - https://www.mendeley.com/catalogue/dc7b3a56-4f0e-356b-810b-ececec09fb99/

U2 - 10.1016/j.commatsci.2023.112708

DO - 10.1016/j.commatsci.2023.112708

M3 - Article

VL - 233

JO - Computational Materials Science

JF - Computational Materials Science

SN - 0927-0256

M1 - 112708

ER -