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Investigation of structural and electronic properties by pnictogen substitution in the layered oxypnictides (LaO)Zn Pn ( Pn = P, As, Sb)
Author(s) -
Muhammady Shibghatullah,
Erlyanti Adelya S.,
Widita Rena,
Darma Yudi
Publication year - 2020
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.26090
Subject(s) - pnictogen , antibonding molecular orbital , band gap , fermi level , valence (chemistry) , chemistry , condensed matter physics , crystallography , conduction band , electronic structure , materials science , electron , superconductivity , physics , atomic orbital , organic chemistry , quantum mechanics
We study the structural and electronic properties of p‐type layered oxypnictides (LaO)Zn Pn ( Pn = P, As, Sb), calculated by first principles. Pn substitution from P to Sb increases D 2 d ‐type local symmetry distortions at Zn Pn 4 and OLa 4 tetrahedra. (LaO)ZnP and (LaO)ZnAs exhibit direct band gaps (Γ → Γ) of 0.621 eV and 0.528 eV, respectively, while (LaO)ZnSb exhibits an indirect band gap (Γ → 0.2Λ) of 0.029 eV. The band gaps come from valence Pn p x /p y and conduction Zn 4s states. Moreover, the substitution increases split‐off energy at Z and Γ points. We find localized valence degeneracy‐lifted Zn 3d states because of the possible second‐order Jahn‐Teller effect, which induces the local symmetry distortions. The localized Zn 3d states are followed by minor bonding s‐p hybridization of Zn and Pn . Above them, we show major bonding s‐p hybridization; O 2p states in electron‐blocking [LaO] + layers, which are essential for thermoelectricity; and nonbonding Pn p states near Fermi level. In the conduction band, antibonding s‐p hybridization is found. Our result shows new insights and findings of structural and electronic properties, which explain previous experimental results, as the focus of this study is related to inorganic chemistry. This study is important for future functional device applications.