Synthesis, characterization and tunable electronic/optical properties of II-VI semiconductor species included in the sodalite structure

authored by: Kelly L. Moran, William T.A. Harrison, Ivo Kamber, Thurman E. Gier, Xianhui Bu, Daniel Herren, Peter Behrens, Hellmut Eckert, Galen D. Stucky
Abstract: The composition-dependent optical and electronic tunability of the sodalite analogues with stoichiometries Zn₈X₂[BO₂] ₁₂ (X = O, S, Se) and [Cd_yZn_(1-y)] ₈X₂[BeSi_xGe_(1-x)O₄] ₆ (X = S, Se and Te) have been demonstrated. The materials strongly photoluminesce, and a comparison of the photoluminescence behavior of the single crystals with the as-synthesized powder analogues shows that the visible emission is intrinsic to the sodalite analogue and not due to impurities such as bulk semiconductor. The emission maxima of these materials can be varied by as much as 100 nm with subtle modifications in the host sodalite framework composition and excitation energies can be stored over, at minimum, several minutes. The materials can be prepared either hydrothermally or by high-temperature solid-state reactions. The local and average long-range structures of composition Zn₈X₂[BO₂] ₁₂ (X = O, S, Se) and M₈X₂[BeSi _xGe_1-xO₄]₆ (M = Zn, Cd; X ) S, Se, Te) are described based on the results of polycrystalline X-ray diffraction, multinuclear solid-state MAS NMR, CdL₃ XANES, UV/visible and photoluminescence spectroscopic measurements. Additionally, the crystal structures of the synthetic helvite solid solutions Zn₈S ₂[BeSi_xGe_1-xO₄]₆ (x = 0.03, 0.37, 0.74) are presented based on refinement of single-crystal X-ray diffraction and selected area electron diffraction data; these materials crystallize in the acentric, cubic space group P23 (No. 195) with unit-cell parameters a = 8.250(4), 8.221(2), and 8.163(1) Å, respectively. In all these sodalite analogues, the anionic, rigid sodalite framework encloses [M ₄X]⁶⁺ tetrahedra in a crystalline cubic array, separating each tetrahedron from its eight nearest neighbors by at least 6.4 Å, center to center. This electrostatic isolation results in dramatic high-energy shifts in the optical absorption spectra of the materials and low-frequency shifts in the MAS NMR spectra of the cage center anions, relative to the bulk semiconductors. ¹¹³Cd MAS NMR and CdL₃ XANES spectra show that the influence of the anion type on the electronic structure at the Cd ²⁺ ions in the cadmium sodalites is small.
External Organisation(s): University of California at Santa Barbara
University of Minnesota
University of Western Australia
Paul Scherrer Institut (PSI)
Phytomed Armand Kilchherr
Ludwig-Maximilians-Universität München (LMU)
Type: Article
Journal: Chemistry of materials
Volume: 8
Pages: 1930-1943
No. of pages: 14
ISSN: 0897-4756
Publication date: 12.1996
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Chemistry, General Chemical Engineering, Materials Chemistry
Electronic version(s): https://doi.org/10.1021/cm960168c (Access: Closed)

BibTeX

@article{d096078d7a724613bb5f5316e326ef2c,
title = "Synthesis, characterization and tunable electronic/optical properties of II-VI semiconductor species included in the sodalite structure",
abstract = "The composition-dependent optical and electronic tunability of the sodalite analogues with stoichiometries Zn8X2[BO2] 12 (X = O, S, Se) and [CdyZn(1-y)] 8X2[BeSixGe(1-x)O4] 6 (X = S, Se and Te) have been demonstrated. The materials strongly photoluminesce, and a comparison of the photoluminescence behavior of the single crystals with the as-synthesized powder analogues shows that the visible emission is intrinsic to the sodalite analogue and not due to impurities such as bulk semiconductor. The emission maxima of these materials can be varied by as much as 100 nm with subtle modifications in the host sodalite framework composition and excitation energies can be stored over, at minimum, several minutes. The materials can be prepared either hydrothermally or by high-temperature solid-state reactions. The local and average long-range structures of composition Zn8X2[BO2] 12 (X = O, S, Se) and M8X2[BeSi xGe1-xO4]6 (M = Zn, Cd; X ) S, Se, Te) are described based on the results of polycrystalline X-ray diffraction, multinuclear solid-state MAS NMR, CdL3 XANES, UV/visible and photoluminescence spectroscopic measurements. Additionally, the crystal structures of the synthetic helvite solid solutions Zn8S 2[BeSixGe1-xO4]6 (x = 0.03, 0.37, 0.74) are presented based on refinement of single-crystal X-ray diffraction and selected area electron diffraction data; these materials crystallize in the acentric, cubic space group P23 (No. 195) with unit-cell parameters a = 8.250(4), 8.221(2), and 8.163(1) {\AA}, respectively. In all these sodalite analogues, the anionic, rigid sodalite framework encloses [M 4X]6+ tetrahedra in a crystalline cubic array, separating each tetrahedron from its eight nearest neighbors by at least 6.4 {\AA}, center to center. This electrostatic isolation results in dramatic high-energy shifts in the optical absorption spectra of the materials and low-frequency shifts in the MAS NMR spectra of the cage center anions, relative to the bulk semiconductors. 113Cd MAS NMR and CdL3 XANES spectra show that the influence of the anion type on the electronic structure at the Cd 2+ ions in the cadmium sodalites is small.",
author = "Moran, {Kelly L.} and Harrison, {William T.A.} and Ivo Kamber and Gier, {Thurman E.} and Xianhui Bu and Daniel Herren and Peter Behrens and Hellmut Eckert and Stucky, {Galen D.}",
year = "1996",
month = dec,
doi = "10.1021/cm960168c",
language = "English",
volume = "8",
pages = "1930--1943",
journal = "Chemistry of materials",
issn = "0897-4756",
publisher = "American Chemical Society",
number = "8",
}