skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Rb 2 CuX 3 (X = Cl, Br): 1D All‐Inorganic Copper Halides with Ultrabright Blue Emission and Up‐Conversion Photoluminescence
Title: Rb 2 CuX 3 (X = Cl, Br): 1D All‐Inorganic Copper Halides with Ultrabright Blue Emission and Up‐Conversion Photoluminescence
Abstract All‐inorganic metal halides such as Cs4PbX6and CsPbX3(X = Cl, Br, and I) are attracting global attention owing to their promise in optoelectronic applications. However, the presence of the toxic heavy metal lead (Pb) in these materials is a major concern. Here, a family of nontoxic high‐efficiency blue‐emitting all‐inorganic halides Rb2CuX3(X = Br and Cl) is reported; the compounds exhibit 1D crystal structures featuring anionic2−ribbons separated by Rb+cations. The measured record high photoluminescence quantum yield values range from 64% to 100% for Rb2CuBr3and Rb2CuCl3, respectively. Furthermore, the measured emission linewidths are quite narrow with full width at half maximum values of 54 and 52 nm for Rb2CuBr3and Rb2CuCl3, respectively. Single crystals of Rb2CuCl3demonstrate an anti‐Stokes photoluminescence signal, shown for the first time for Pb‐free metal halides. The discovery of highly efficient narrow blue emitters based on a nontoxic and inexpensive metal copper paves a way for the consideration of low‐cost and environmentally friendly copper halides for practical applications.  more » « less
Award ID(s):
1726630
PAR ID:
10458978
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Advanced Optical Materials
Volume:
8
Issue:
2
ISSN:
2195-1071
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; (, Advanced Functional Materials)
    Abstract Copper(I) halides are emerging as attractive alternatives to lead halide perovskites for optical and electronic applications. However, blue‐emitting all‐inorganic copper(I) halides suffer from poor stability and lack of tunability of their photoluminescence (PL) properties. Here, the preparation of silver(I) halides A2AgX3(A = Rb, Cs; X = Cl, Br, I) through solid‐state synthesis is reported. In contrast to the Cu(I) analogs, A2AgX3are broad‐band emitters sensitive to A and X site substitutions. First‐principle calculations show that defect‐bound excitons are responsible for the observed main PL peaks in Rb2AgX3and that self‐trapped excitons (STEs) contribute to a minor PL peak in Rb2AgBr3. This is in sharp contrast to Rb2CuX3, in which the PL is dominated by the emission by STEs. Moreover, the replacement of Cu(I) with Ag(I) in A2AgX3significantly improves photostability and stability in the air under ambient conditions, which enables their consideration for practical applications. Thus, luminescent inks based on A2AgX3are prepared and successfully used in anti‐counterfeiting applications. The excellent light emission properties, significantly improved stability, simple preparation method, and tunable light emission properties demonstrated by A2AgX3suggest that silver(I) halides may be attractive alternatives to toxic lead halide perovskites and unstable copper(I) halides for optical applications. 
    more » « less
  2. ; ; ; (, Advanced Photonics Research)
    All‐inorganic copper(I) halides have recently emerged as attractive alternatives to lead‐based halide perovskites and rare‐earth‐doped inorganics for light emission applications. Most of the newly discovered all‐inorganic Cu(I) halides demonstrate high‐efficiency blue emission albeit with unusually poor tunability of photoluminescence (PL) properties. This work reports the facile preparation of three new copper(I) halides based on the guanidinium cation: (CN3H6)3CuCl4, (CN3H6)7Cu3Br10·3(C3H7NO), and (CN3H6)7Cu3I10·3(C3H7NO). A comprehensive characterization of PL is presented for these novel materials, which have highly tunable, dual blue–yellow emission responsive to both excitation wavelength and vacuum annealing. These have remarkable photoluminescence quantum yield (PLQY) values of up to 34.6% and color‐rendering indices (CRI) up to 97% for tunable, single‐phase white light emission with correlated color temperatures (CCT) ranging from 4851 to 18 921 K, demonstrating the excellent potential of Cu(I) halides for light emission applications. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; (, Angewandte Chemie International Edition)
    Abstract We incorporate Se into the 3D halide perovskite framework using the zwitterionic ligand: SeCYS (+NH3(CH2)2Se−), which occupies both the X−and A+sites in the prototypical ABX3perovskite. The new organoselenide‐halide perovskites: (SeCYS)PbX2(X=Cl, Br) expand upon the recently discovered organosulfide‐halide perovskites. Single‐crystal X‐ray diffraction and pair distribution function analysis reveal the average structures of the organoselenide‐halide perovskites, whereas the local lead coordination environments and their distributions were probed through solid‐state77Se and207Pb NMR, complemented by theoretical simulations. Density functional theory calculations illustrate that the band structures of (SeCYS)PbX2largely resemble those of their S analogs, with similar band dispersion patterns, yet with a considerable band gap decrease. Optical absorbance measurements indeed show band gaps of 2.07 and 1.86 eV for (SeCYS)PbX2with X=Cl and Br, respectively. We further demonstrate routes to alloying the halides (Cl, Br) and chalcogenides (S, Se) continuously tuning the band gap from 1.86 to 2.31 eV–straddling the ideal range for tandem solar cells or visible‐light photocatalysis. The comprehensive description of the average and local structures, and how they can fine‐tune the band gap and potential trap states, respectively, establishes the foundation for understanding this new perovskite family, which combines solid‐state and organo‐main‐group chemistry. 
    more » « less
  4. ; ; ; ; ; ; ; ; (, Aggregate)
    Abstract Highly sensitive stimuli‐responsive luminescent materials are crucial for applications in optical sensing, security, and anticounterfeiting. Here, we report two zero‐dimensional (0D) copper(I) halides, (TEP)2Cu2Br4, (TEP)2Cu4Br6, and 1D (TEP)3Ag6Br9, which are comprised of isolated [Cu2Br4]2−, [Cu4Br6]2−, and [Ag6Br9]3−polyanions, respectively, separated by TEP+(tetraethylphosphonium [TEP]) cations. (TEP)2Cu2Br4and (TEP)2Cu4Br6demonstrate greenish‐white and orange‐red emissions, respectively, with near unity photoluminescence quantum yields, while (TEP)3Ag6Br9is a poor light emitter. Optical spectroscopy measurements and density‐functional theory calculations reveal that photoemissions of these compounds originate from self‐trapped excitons due to the excited‐state distortions in the copper(I) halide units. Crystals of Cu(I) halides are radioluminescence active at room temperature under both X‐ and γ‐rays exposure. The light yields up to 15,800 ph/MeV under 662 keV γ‐rays of137Cs suggesting their potential for scintillation applications. Remarkably, (TEP)2Cu2Br4and (TEP)2Cu4Br6are interconvertible through chemical stimuli or reverse crystallization. In addition, both compounds demonstrate luminescence on‐off switching upon thermal stimuli. The sensitivity of (TEP)2Cu2Br4and (TEP)2Cu4Br6to the chemical and thermal stimuli coupled with their ultrabright emission allows their consideration for applications such as solid‐state lighting, sensing, information storage, and anticounterfeiting. 
    more » « less
  5. ; ; ; ; ; ; (, Small)
    Abstract Birefringent materials are widely used in various advanced optical systems, owing to their vital role in creating and controlling polarized light. Currently, Sn2+‐based compounds containing stereochemically active lone‐pair (SCALP) cations are extensively investigated and considered as one class of promising birefringent materials. To solve the problem of relatively narrow bandgap of Sn2+‐based compounds, alkali metals and multiple halogens are introduced to widen the bandgap during the research. Based on this strategy, four new Sn2+‐based halides, A2Sn2F5Cl and ASnFCl2(A = Rb and Cs), with large birefringence, short ultraviolet (UV) cutoff edge, and wide transparent range are successfully found. The birefringences of A2Sn2F5Cl (A = Rb and Cs) are 0.31 and 0.28 at 532 nm, respectively, which are among the largest in Sn‐based halide family. Remarkably, A2Sn2F5Cl possess relatively shorter UV cutoff edge (<300 nm) and broad infrared (IR) transparent range (up to 16.6 µm), so they can become promising candidates as birefringent materials applied in both UV and IR regions. In addition, a comprehensive analysis on crystal structures and structure–property relationship of metal Sn2+‐based halides is performed to fully understand this family. Therefore, this work provides insights into designing birefringent materials with balanced optical properties. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email