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.
This content will become publicly available on December 15, 2024
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- NSF-PAR ID:
- 10480034
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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