Single crystal growth, electronic structure and optical properties of Cs2HgBr4

Lavrentyev, A.A.; Gabrelian, B.V.; Vu, Tuan V.; Shkumat, P.N.; Parasyuk, O.V.; Fedorchuk, A.O.; Khyzhun, O.Y.

doi:10.1016/j.jpcs.2015.06.004

Cited by 15 publications

(5 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The decrease of the content of mercury atoms within the top near-surface analyzing layers of the Tl 2 HgGeSe 4 crystal is accompanied by changes in the shape of the valence electron energy allocations, mainly in the region relating to the area just below the main portion of the valence band (Figure ). It is worth indicating that the effect of decreasing mercury content was found to be very pronounced in Cs 2 HgQ 4 (Q = Cl, Br, and I) halides: the 3 kV Ar + ion-beam-induced treatment, in some cases, leads to a decrease in its content in several times. ,, …”

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

“…It is worth indicating that the effect of decreasing mercury content was found to be very pronounced in Cs 2 HgQ 4 (Q = Cl, Br, and I) halides: the 3 kV Ar + ion-beam-induced treatment, in some cases, leads to a decrease in its content in several times. 62,74,75 It is well known that for evaluating the degree of ionicity of the chemical bonding, it is very helpful to deal with the XPS difference parameters Δ: the bigger parameter Δ value determined as the BE difference of the core-level electrons related to a cation and an anion, the higher onicity degree of the cation−anion bonds. 76 Following the aim to evaluate comparatively the peculiarities of the chemical bonding of the Tl 2 HgGeSe 4 crystal with those of related germaniumcontaining counterparts, we collected in Table 4 the results of determining the difference Δ Tl , Δ Hg , and Δ Ge parameters that were calculated based on the differences of experimentally measured binding energies of Tl 4f 7/2 , Hg 4f 7/2 , and Ge 3d electrons, respectively, and Se 3d electrons.…”

Section: Crystal Structure and First-principles Calculationsmentioning

confidence: 99%

“…Such optical constants as α(ω) (optical absorption coefficient), n (ω) (refractive index), k (ω) (extinction coefficient), R (ω) (optical coefficient of reflectivity), and L (ω) (spectrum of electron energy loss) could be obtained from real and imaginary portions, ε 1 (ω) and ε 2 (ω), of the dielectric function via equations α i j ( ω ) = 2 ω k i j ( ω ) c n i j ( ω ) = 1 2 false[ ε 1 i j false( ω false) 2 + ε 2 i j false( ω false) 2 + ε 1 i j ( ω ) false] 1 / 2 k i j ( ω ) = 1 2 false[ ε 1 i j false( ω false) 2 + ε 2 i j false( ω false) 2 .25em − .25em ε 1 i j ( ω ) false] 1 / ...…”

Section: Crystal Structure and First-principles Calculationsmentioning

confidence: 99%

Section: Crystal Structure and First-principles Calculationsmentioning

confidence: 99%

See 4 more Smart Citations

Insights from Experiment and Theory on Peculiarities of the Electronic Structure and Optical Properties of the Tl₂HgGeSe₄ Crystal

Vu,

Khyzhun,

Myronchuk

et al. 2023

Inorg. Chem.

View full text Add to dashboard Cite

Tl 2 HgGeSe 4 crystal was successfully, for the first time, synthesized by the Bridgman−Stockbarger technology, and its electronic structure and peculiarities of optical constants were investigated using both experimental and theoretical techniques. The present X-ray photoelectron spectroscopy measurements show that the Tl 2 HgGeSe 4 crystal reveals small moisture sensitivity at ambient conditions and that the essential covalent constituent of the chemical bonding characterizes it. The latter suggestion was supported theoretically by ab initio calculations. The present experiments feature that the Tl 2 HgGeSe 4 crystal is a high-resistance semiconductor with a specific electrical conductivity of σ ∼ 10 −8 Ω −1 cm −1 (at 300 K). The crystal is characterized by p-type electroconductivity with an indirect energy band gap of 1.28 eV at room temperature. It was established that a good agreement with the experiments could be obtained when performing first-principles calculations using the modified Becke−Johnson functional as refined by Tran−Blaha with additional involvement in the calculating procedure of the Hubbard amendment parameter U and the impact of spin−orbit coupling (TB-mBJ + U + SO model). Under such a theoretical model, we have determined that the energy band gap of the Tl 2 HgGeSe 4 crystal is equal to 1.114 eV, and this band gap is indirect in nature. The optical constants of Tl 2 HgGeSe 4 are calculated based on the TB-mBJ + U + SO model.

show abstract

Section: Resultsmentioning

confidence: 98%