An official website of the United States government
Evolution of Yb 3+ Speciation in Cl – /Br – - and Yb 3+ /Gd 3+ -Alloyed Quantum-Cutting Lead-Halide Perovskite Nanocrystals
- PAR ID:
- 10469279
- Publisher / Repository:
- Chemistry of Materials
- Date Published:
- Journal Name:
- Chemistry of Materials
- Volume:
- 35
- Issue:
- 19
- ISSN:
- 0897-4756
- Page Range / eLocation ID:
- 8057 to 8064
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
The local atomic environment of Yb 3+ ions doped into Yb:Er:SrFCl, Yb:Er:SrFBr, and Yb:Er:BaFCl nanocrystals was probed using Yb L 2 edge EXAFS spectroscopy. A structural model derived from substitution of Yb 3+ for Sr 2+ or Ba 2+ in the fluorohalide lattice failed to provide a crystallochemically meaningful description of the first coordination shell of Yb 3+ . On this basis, the presence of Yb 3+ coordinated as YbF 4 Cl 5 or YbF 4 Br 5 capped square antiprisms of C 4 v symmetry was ruled out. Two alternative models were evaluated. The first model was inspired by YbF 9 capped square antiprisms that make up the crystal structure of orthorhombic YbF 3 . The second model was based on YbO 4 F 3 capped trigonal prisms encountered in monoclinic YbOF. Both models correctly reproduced radial structure functions and yielded chemically meaningful ytterbium–fluorine and ytterbium–oxygen distances. Results from EXAFS studies indicate that compositional and structural heterogeneities appear in the fluorohalide lattice upon aliovalent doping with Yb 3+ . From a compositional standpoint, extra fluoride anions and/or oxide anions appear to be incorporated in the vicinity of Yb 3+ dopants. From a structural standpoint, the local symmetry around Yb 3+ ( C s or C 1 ) is lower than that of the crystallographic sites occupied by alkaline-earth cations. These conclusions hold for three different fluorohalide host compositions and rare-earth doping levels spanning one order of magnitude.more » « less
-
Luminescent solar concentrators (LSCs) can concentrate direct and diffuse solar radiation spatially and energetically to help reduce the overall area of solar cells needed to meet current energy demands. LSCs require luminophores that absorb large fractions of the solar spectrum, emit photons into a light-capture medium with high photoluminescence quantum yields (PLQYs), and do not absorb their own photoluminescence. Luminescent nanocrystals (NCs) with near or above unity PLQYs and Stokes shifts large enough to avoid self-absorption losses are well-suited to meet these needs. In this work, we describe LSCs based on quantum-cutting Yb 3+ :CsPb(Cl 1−x Br x ) 3 NCs that have documented PLQYs as high as ∼200%. Through a combination of solution-phase 1D LSC measurements and modeling, we demonstrate that Yb 3+ :CsPbCl 3 NC LSCs show negligible intrinsic reabsorption losses, and we use these data to model the performance of large-scale 2D LSCs based on these NCs. We further propose a new and unique monolithic bilayer LSC device architecture that contains a Yb 3+ :CsPb(Cl 1−x Br x ) 3 NC top layer above a second narrower-gap LSC bottom layer ( e.g. , based on CuInS 2 NCs), both within the same waveguide and interfaced with the same Si PV for conversion. We extend the modeling to predict the flux gains of such bilayer devices. Because of the exceptionally high PLQYs of Yb 3+ :CsPb(Cl 1−x Br x ) 3 NCs, the optimized bilayer device has a projected flux gain of 63 for dimensions of 70 × 70 × 0.1 cm 3 , representing performance enhancement of at least 19% over the optimized CuInS 2 LSC alone.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1021/acs.chemmater.3c01475
