Synthesis, crystal and electronic structures and optical properties of (HIm)₂ Hg₃Cl₈ and (HIm)HgI₃ (HIm = imidazolium)

Journal Article · Wed Nov 22 00:00:00 EST 2017 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2017.11.028· OSTI ID:1410913

Nhalil, Hariharan ^[1]; Whiteside, Vincent R. ^[2]; Sellers, Ian R. ^[2]; Ming, Wenmei ^[3]; Du, Mao-Hua ^[3]; Saparov, Bayrammurad ^[1]

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1. Univ. of Oklahoma, Norman, OK (United States). Dept. of Chemistry and Biochemistry
2. Univ. of Oklahoma, Norman, OK (United States). Homer L. Dodge Dept. of Physics & Astronomy
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division

Here, we report synthesis, crystal and electronic structures, and optical properties of two new Hg-based zero-dimensional hybrid organic-inorganic halides (HIm)2Hg3Cl8 and (HIm)HgI3 (HIm = imidazolium). (HIm)₂Hg₃Cl₈ crystallizes in the triclinic P-1 space group with a pseudo-layered structure made of organic imidazolium cation layers and anionic inorganic layers containing [Hg₂Cl₆]^2- units and linear [HgCl₂]⁰ molecules. (HIm)HgI₃ crystallizes in the monoclinic P2₁/c space group featuring anionic [HgI₃]- units that are surrounded by imidazolium cations. Based on density functional theory calculations, (HIm)₂Hg₃Cl₈ has an indirect band gap, whereas (HIm)HgI₃ has a direct band gap with the measured onsets of optical absorption at 3.43 and 2.63 eV, respectively. (HIm)₂Hg₃Cl₈ and (HIm)HgI₃ are broadband light emitters with broad photoluminescence peaks centered at 548 nm (2.26 eV) and 582 nm (2.13 eV), respectively. In conclusion, following the crystal and electronic structure considerations, the PL peaks are assigned to self-trapped excitons.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1410913
• Journal Information: Journal of Solid State Chemistry, Vol. 258, Issue C; ISSN 0022-4596
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Hybrid organic-inorganic halides
Optoelectronic halides
Photoluminescence
Band structure calculations