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Electronic structure and band gap of oxygen bearing c‐ Z r 3 N 4 and of c‐ H f 3 N 4 by soft X‐ray spectroscopy
Author(s) -
Yablonskikh Mikhail,
Dzivenko Dmytro,
Bourguille Judith,
Riedel Ralf,
Magnano Elena,
Parmigiani Fulvio,
Zerr Andreas
Publication year - 2014
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201330338
Subject(s) - band gap , electronic structure , crystallography , analytical chemistry (journal) , nitride , chemistry , absorption spectroscopy , oxygen , materials science , computational chemistry , nanotechnology , physics , optoelectronics , chromatography , layer (electronics) , quantum mechanics , organic chemistry
Electronic band structures of two novel semiconducting nitrides of the group‐IV elements of Th 3 P 4 ‐type crystal structure, c‐M 3 N 4 , where MZr or Hf, is investigated using an element specific soft X‐ray spectroscopy for the first time. From the pairs of N 1s X‐ray absorption and N 2p → 1s resonant X‐ray emission spectra partial densities of states (PDOS) of nitrogen, predicted to be strongly hybridized with those of the metals, are obtained for both compounds. From these data the electronic band gaps of oxygen bearing c‐Zr 3 N 4 and of c‐Hf 3 N 4 , predicted before to be direct or nearly direct, are derived to be E g = 1.6 eV and E g = 1.8 eV, respectively. While the experimentally determined E g for c‐Hf 3 N 4 agrees with the theoretical one obtained using the local density approximation (LDA) method, the E g measured for oxygen bearing c‐Zr 3 N 4 is significantly higher than those calculated using both the LDA and the generalized gradient approximation method. The examined compounds, having high hardness, elastic moduli and oxidation resistance, appear to be multifunctional materials suitable also for applications as (opto)electronic materials. Band gap evolution in c‐M 3 N 4 nitrides as a function of the cation type, Zr or Hf.