J 2016

Accurate prediction of band gaps and optical properties of HfO2

ONDRAČKA, Pavel, David HOLEC, David NEČAS and Lenka ZAJÍČKOVÁ

Basic information

Original name

Accurate prediction of band gaps and optical properties of HfO2

Authors

ONDRAČKA, Pavel (203 Czech Republic, belonging to the institution), David HOLEC (40 Austria), David NEČAS (203 Czech Republic, belonging to the institution) and Lenka ZAJÍČKOVÁ (203 Czech Republic, guarantor, belonging to the institution)

Edition

JOURNAL OF PHYSICS D-APPLIED PHYSICS, Bristol, Institute of Physics Publishing, 2016, 0022-3727

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10306 Optics

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 2.588

RIV identification code

RIV/00216224:14740/16:00094067

Organization unit

Central European Institute of Technology

DOI

UT WoS

000404341800001

Keywords in English

band gap; BSE; DFT; dielectric function; hafnia; HfO2; TB-mBJ

Tags

Změněno: 28/3/2019 16:09, Mgr. Pavla Foltynová, Ph.D.

Abstract

V originále

We report on optical properties of various polymorphs of hafnia predicted within the framework of density functional theory. The full potential linearised augmented plane wave method was employed together with the Tran-Blaha modified Becke-Johnson potential (TB-mBJ) for exchange and local density approximation for correlation. Unit cells of monoclinic, cubic and tetragonal crystalline, and a simulated annealing-based model of amorphous hafnia were fully relaxed with respect to internal positions and lattice parameters. Electronic structures and band gaps for monoclinic, cubic, tetragonal and amorphous hafnia were calculated using three different TB-mBJ parametrisations and the results were critically compared with the available experimental and theoretical reports. Conceptual differences between a straightforward comparison of experimental measurements to a calculated band gap on the one hand and to a whole electronic structure (density of electronic states) on the other hand, were pointed out, suggesting the latter should be used whenever possible. Finally, dielectric functions were calculated at two levels, using the random phase approximation without local field effects and with a more accurate Bethe-Salpether equation (BSE) to account for excitonic effects. We conclude that a satisfactory agreement with experimental data for HfO2 was obtained only in the latter case.

Links

LQ1601, research and development project
Name: CEITEC 2020 (Acronym: CEITEC2020)
Investor: Ministry of Education, Youth and Sports of the CR
7AMB15AT017, research and development project
Name: Studium struktury elektronických a optických vlastností tuhých roztoků oxidů s využitím ab initio výpočtů
Investor: Ministry of Education, Youth and Sports of the CR