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Title: Electronic shell structures, self-trapped excitons, and defect-bound excitons in Li2B12H12

Journal Article · · Journal of Materials Chemistry C
DOI: https://doi.org/10.1039/c9tc04150h · OSTI ID:1607243
ORCiD logo [1]; ORCiD logo [2];  [3]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
  2. Key Laboratory of Micro-Nano Measurement-Manipulation and Physics (Ministry of Education); Department of Physics; Beihang University; Beijing 100191; China
  3. Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Electrical, Computer and Systems Engineering

First-principles studies of electronic structures, excitons, and defects in Li2B12H12 reveal unique photophysical properties of Li2B12H12 and its potential as a neutron scintillator material. We identify the electronic shell structure in (B12H12)2-, which gives rise to strong chemical stability of (B12H12)2- and a large band gap of Li2B12H12. Based on hybrid functional calculations, we show that excitons in Li2B12H12 are strongly self-trapped and predict that the exciton excitation and emission are both in the UV range and are not related to the bright blue emission observed in the experiment. The experimentally observed blue emission in Li2B12H12 is likely due to the emission of excitons bound to hydrogen vacancies. The calculated strong localization and large exciton trapping energy at hydrogen vacancies indicate enhanced radiative recombination, while the calculated large Stokes shift suggests that the self-absorption and the resonance transfer of the excitation energy may be suppressed. These properties should promote efficient defect emission at room temperature. The efficient defect emission, combined with the large thermal neutron capture cross-section by Li and B and the efficient energy transfer between fast neutrons and H, suggests potential applications of Li2B12H12 as a thermal or fast neutron scintillator. Optical characterization of VH may also be used to monitor H and Li concentrations in Li2B12H12-based hydrogen storage materials and solid-state electrolytes in Li batteries.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1607243
Journal Information:
Journal of Materials Chemistry C, Journal Name: Journal of Materials Chemistry C Journal Issue: 45 Vol. 7; ISSN JMCCCX; ISSN 2050-7526
Publisher:
Royal Society of ChemistryCopyright Statement
Country of Publication:
United States
Language:
English

References (66)

Lead-Free Highly Efficient Blue-Emitting Cs 3 Cu 2 I 5 with 0D Electronic Structure journal September 2018
Rational Design of Nanosized Light Elements for Hydrogen Storage: Classes, Synthesis, Characterization, and Properties journal February 2018
Formation and Diffusion of Metal Impurities in Perovskite Solar Cell Material CH 3 NH 3 PbI 3 : Implications on Solar Cell Degradation and Choice of Electrode journal December 2017
Carbon Incorporation and Anion Dynamics as Synergistic Drivers for Ultrafast Diffusion in Superionic LiCB 11 H 12 and NaCB 11 H 12 journal February 2018
A Zero-Dimensional Organic Seesaw-Shaped Tin Bromide with Highly Efficient Strongly Stokes-Shifted Deep-Red Emission journal December 2017
Highly Emissive Self-Trapped Excitons in Fully Inorganic Zero-Dimensional Tin Halides journal July 2018
A Zero-Dimensional Organic Seesaw-Shaped Tin Bromide with Highly Efficient Strongly Stokes-Shifted Deep-Red Emission journal December 2017
Highly Emissive Self-Trapped Excitons in Fully Inorganic Zero-Dimensional Tin Halides journal July 2018
Formation of Al13I-: Evidence for the Superhalogen Character of Al13. journal June 2004
Borane Derivatives: A New Class of Super- and Hyperhalogens journal July 2011
Dual behavior of excess electrons in rutile TiO 2 journal January 2013
Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set journal July 1996
Critical review, with an optimistic outlook, on Boron Neutron Capture Therapy (BNCT) journal June 2014
Metal boranes: Progress and applications journal September 2016
Complex high-temperature phase transitions in Li2B12H12 and Na2B12H12 journal April 2014
Low dimensional metal halide perovskites and hybrids journal July 2019
White-Light Emission from Layered Halide Perovskites journal February 2018
Structural, Chemical, and Dynamical Frustration: Origins of Superionic Conductivity in closo -Borate Solid Electrolytes journal October 2017
Fast Lithium-Ion Conduction in Atom-Deficient closo -Type Complex Hydride Solid Electrolytes journal January 2018
Facile Preparation of Light Emitting Organic Metal Halide Crystals with Near-Unity Quantum Efficiency journal March 2018
Predicting Band Gaps with Hybrid Density Functionals journal October 2016
Near-Unity Photoluminescence Quantum Yield in Blue-Emitting Cs 3 Cu 2 Br 5– x I x (0 ≤ x ≤ 5) journal February 2019
A One-Dimensional Organic Lead Chloride Hybrid with Excitation-Dependent Broadband Emissions journal May 2018
Green Emitting Single-Crystalline Bulk Assembly of Metal Halide Clusters with Near-Unity Photoluminescence Quantum Efficiency journal June 2019
Broadband Emission in Hybrid Organic–Inorganic Halides of Group 12 Metals journal December 2018
Three-Dimensional Aromaticity in Polyhedral Boranes and Related Molecules journal May 2001
Applications of Radiolabeled Boron Clusters to the Diagnosis and Treatment of Cancer journal December 1999
Antiaromaticity in Bare Deltahedral Silicon Clusters Satisfying Wade's and Hirsch's Rules:  An Apparent Correlation of Antiaromaticity with High Symmetry journal December 2003
Thermal Stability of Li 2 B 12 H 12 and its Role in the Decomposition of LiBH 4 journal April 2013
The renaissance of hydrides as energy materials journal December 2016
Reducing Dzyaloshinskii-Moriya interaction and field-free spin-orbit torque switching in synthetic antiferromagnets journal May 2021
High-resolution X-ray luminescence extension imaging journal February 2021
Chemical trends of Mn 4+ emission in solids journal January 2014
Bi-functional Li 2 B 12 H 12 for energy storage and conversion applications: solid-state electrolyte and luminescent down-conversion dye journal January 2015
Synthesis, stability and Li-ion mobility of nanoconfined Li 2 B 12 H 12 journal January 2017
Luminescent zero-dimensional organic metal halide hybrids with near-unity quantum efficiency journal January 2018
Comment on “Bi-functional Li 2 B 12 H 12 for energy storage and conversion applications: solid-state electrolyte and luminescent down-conversion dye” by J. A. Teprovich Jr, H. Colón-Mercado, A. L. Washington II, P. A. Ward, S. Greenway, D. M. Missimer, H. Hartman, J. Velten, J. H. Christian and R. Zidan, J. Mater. Chem. A , 2015, 3 , 22853 journal January 2019
Unraveling luminescence mechanisms in zero-dimensional halide perovskites journal January 2018
Reply to the ‘Comment on “Bi-functional Li 2 B 12 H 12 for energy storage and conversion applications: solid-state electrolyte and luminescent down-conversion dye”’ by M. Paskevicius, A. S. Jakobsen, M. Bregnhøj, B. R. S. Hansen, K. T. Møller, P. R. Ogilby and T. R. Jensen, J. Mater. Chem. A. , 2019, DOI: 10.1039/c8ta10735a journal January 2019
Zero-dimensional metal oxide Li 4 TiO 4 journal January 2019
First-order phase transition in the Li2B12H12 system journal January 2013
Hybrid functionals based on a screened Coulomb potential journal May 2003
Potential-energy surfaces for excited states in extended systems journal March 2004
Screened hybrid density functionals applied to solids journal April 2006
Influence of the exchange screening parameter on the performance of screened hybrid functionals journal December 2006
Rationale for mixing exact exchange with density functional approximations journal December 1996
Small hole polarons in rare-earth titanates journal June 2015
Neutron scattering lengths and cross sections journal January 1992
Density-functional theory beyond the Hohenberg-Kohn theorem journal May 1999
Discrete Electronic Bands in Semiconductors and Insulators: Potential High-Light-Yield Scintillators journal May 2015
Efficient pseudopotentials for plane-wave calculations journal January 1991
Structural and electronic properties of C 60 journal July 1992
Born-Oppenheimer molecular-dynamics simulations of finite systems: Structure and dynamics of ( H 2 O ) 2 journal July 1993
From ultrasoft pseudopotentials to the projector augmented-wave method journal January 1999
Assessment of correction methods for the band-gap problem and for finite-size effects in supercell defect calculations: Case studies for ZnO and GaAs journal December 2008
Impurity-bound small polarons in ZnO: Hybrid density functional calculations journal September 2009
Energy transport and scintillation of cerium-doped elpasolite Cs 2 LiYCl 6 : Hybrid density functional calculations journal July 2012
Vacancies and small polarons in SrTiO 3 journal August 2014
Generalized Gradient Approximation Made Simple journal October 1996
Impact of metal n s 2 lone pair on luminescence quantum efficiency in low-dimensional halide perovskites journal March 2019
The density functional formalism, its applications and prospects journal July 1989
The physics of simple metal clusters: experimental aspects and simple models journal July 1993
Formation of Al13I-: Evidence for the Superhalogen Character of Al13 journal April 2004
Al Cluster Superatoms as Halogens in Polyhalides and as Alkaline Earths in Iodide Salts journal January 2005
Predicting Band Gaps with Hybrid Density Functionals text January 2016
An ultrasensitive molybdenum-based double-heterojunction phototransistor text January 2021