We report the one-pot synthesis of colloidal Mn-doped cesium lead halide (CsPbX3) perovskite nanocrystals and efficient intraparticle energy transfer between exciton dopant ions resulting in intense sensitized Mn luminescence. CsPbCl3 CsPb(Cl/Br)3 maintained same lattice structure crystallinity as their undoped counterparts with nearly identical parameters at ∼0.2% doping concentrations no signature phase separation. The strong luminescence from d–d transition Mn2+ upon band-edge excitation...

We have designed a facile synthetic strategy for the selective deposition of Au metal on all-inorganic CsPbBr3 perovskite nanocrystals that includes addition PbBr2 salt along with AuBr3 salt. is necessary because Au3+ to solutions otherwise results in exchange ions from solution Pb2+ cations within nanocrystal lattice produce Cs2AuIAuIIIBr6 tetragonal crystal structure and band gap about 1.6 eV, deposition. Including excess prevents reaction. deposits surface Au-CsPbBr3 heterostructure...

Plasmonic nanocrystals in close-packed assemblies exhibit collective optical resonance and strongly concentrated electric fields due to coupling. The spectral red-shift from the localized surface plasmon (LSPR) of isolated that an assembly reflects coupling strength, which depends on nanocrystal characteristics structure. Scaling laws relate these shifts spacing are useful systematically describe predict peak for materials design. Here, we develop a unified scaling relationship accounts...

Plasmon polaritons created by coupling optical cavity modes with plasmonic resonances offer widely tunable frequencies and strong light-matter interaction. While metallic nanocrystals (NCs) are compelling building blocks, existing approaches for their photonic integration not scalable, limiting systematic study potential applications. Here, we assemble colloidal tin-doped indium oxide NCs in a straightforward Salisbury screen configuration to realize an 'open' structure, where the infrared...

Optical properties of nanoparticle assemblies reflect distinctive characteristics their building blocks and spatial organization, giving rise to emergent phenomena. Integrated experimental computational studies have established design principles connecting the structure for assembled clusters superlattices. However, conventional electromagnetic simulations are too computationally expensive treat more complex assemblies. Here we establish a fast, materials agnostic method simulate optical...

The ability to efficiently absorb light in ultrathin (subwavelength) layers is essential for modern electro-optic devices, including detectors, sensors, and nonlinear modulators. Tailoring these films' spectral, spatial, polarimetric properties highly desirable many, if not all, of the above applications. Doing so, however, often requires costly lithographic techniques or exotic materials, limiting scalability. Here we propose, demonstrate, analyze a mid-infrared absorber architecture...

Distinct from noble metal nanoparticles, doped oxide nanocrystals (NCs) exhibit localized surface plasmon resonance (LSPR) in the infrared region that can be tuned by changing free electron concentration through both synthetic and postsynthetic doping. Redox reagents have commonly been used to postsynthetically modulate LSPR, but understand relationship between transfer processes resulting optical changes, it is imperative quantify electrons NCs. Titration LSPR peak fitting analysis are most...

Lack of detailed understanding the growth mechanism CsPbBr3 nanocrystals has hindered sophisticated morphological and chemical control this important emerging optoelectronic material. Here, we have elucidated by slowing reaction kinetics. When 1-bromohexane is used as an alternative halide source, bromide slowly released into mixture, extending time from ∼3 s to greater than 20 min. This enables us monitor phase evolution products over course reaction, revealing that CsBr initial species...

Surface functionalization with dipolar molecules is known to tune the electronic band alignment in semiconductor films and colloidal quantum dots. Yet, influence of surface modification on plasmonic nanocrystals their properties remains little explored. Here, we functionalize tin-doped indium oxide (ITO NCs) via ligand exchange a series cinnamic acids different electron-withdrawing -donating characters. Consistent previous reports semiconductors, find that withdrawing (donating) ligands...

Coupling between plasmonic resonances and molecular vibrations in nanocrystals (NCs) offers a promising approach for detecting molecules at low concentrations discerning their chemical identities. Metallic NC superlattices can enhance vibrational signals under far-field detection by generating myriad of intensified electric field hot spots the NCs. Yet, effectiveness is limited fixed electron concentration dictated metal composition inefficient spot creation due to large mode volume. Doped...

Plasmon polaritons created by coupling optical cavity modes with plasmonic resonances offer widely tunable frequencies and strong light–matter interaction. While metallic nanocrystals (NCs) are compelling building blocks, existing approaches for their photonic integration not scalable, limiting systematic study potential applications. Here, we assemble colloidal tin-doped indium oxide NCs in a straightforward Salisbury screen configuration to realize an 'open' structure, where the infrared...

Gelation offers a powerful strategy to assemble plasmonic nanocrystal networks incorporating both the distinctive optical properties of constituent building blocks and customizable collective properties. Beyond what single-component assembly can offer, characteristics be tuned in broader range when two or more components are intimately combined. Here, we demonstrate mixed gel using thermoresponsive metal-terpyridine links that enable rapid disassembly with thermal cycling. Plasmonic indium...

Optically driven cooling of a material, or optical refrigeration, is possible when up-conversion via anti-Stokes photoluminescence (ASPL) achieved with near-unity quantum yield. The recent demonstration CsPbBr3 perovskite nanocrystals (NCs) has provided path forward in the development semiconductor-based refrigeration strategies. However, mechanism ASPL NCs not yet settled, and prospects for technologies strongly depend on details mechanism. By analyzing Arrhenius behavior NCs, we...

CsPbBr₃ nanoparticles that have been treated with NH₄SCN to produce essentially trap-free surfaces show an increase of one photon up-conversion quantum yield little change the energy activation, as estimated using Arrhenius analysis.

One photon up-conversion photoluminescence is an optical phenomenon whereby the thermal energy of a fluorescent material increases emitted compared with that was absorbed. When this occurs near unity efficiency, emitting undergoes net decrease in temperature--so called cooling. Because mechanism thermally activated, yield up-converted also reporter temperature emitter. Taking advantage signature, cesium lead trihalide nanocrystals are shown to cool during 532 nm CW laser excitation. Raman...

The resonant frequency of plasmonic nanoparticles depends on the refractive index local environment, a property which is directly useful for sensing applications and indicative potential utility other based near-field enhancement light intensity. While morphology dependence dielectric sensitivity has been well studied in noble-metal nanoparticles, less investigated degenerately doped metal oxide nanocrystals, whose plasmon resonances lie near- to mid-infrared region. Here, we report fluorine...

The oxidation state of the Au ions determines whether cation exchange or gold deposition occurs when an salt is added to solutions all-inorganic cesium lead halide perovskite nanocrystals.

The ability to efficiently absorb light in ultrathin subwavelength) layers is essential for modern electro-optic devices, including detectors, sensors, and nonlinear modulators. Tailoring these films’ spectral, spatial, polarimetric properties highly desirable many, if not all, of the above applications. Doing so, however, often requires costly lithographic techniques or exotic materials, limiting scalability. Here we propose, demonstrate, analyze a mid-infrared absorber architecture...

Plasmonic nanocrystals in close-packed assemblies exhibit collective optical resonance and strongly concentrated electric fields due to coupling. The spectral redshift from the localized surface plasmon (LSPR) of isolated that an assembly reflects coupling strength, which depends on nanocrystal characteristics structure. Scaling laws relate these shifts spacing are useful systematically describe can be used predict peak for materials design. Here, we develop a unified scaling relationship...

The aim of this work was to fabricate a dense and thin film gadolinium doped ceria (CGO) adherent on yttria-stabilized zirconia (YSZ) using electrostatic spray deposition (ESD) for intermediate temperature solid oxide fuel cells (IT-SOFC) applications. In order optimize the microstructure thickness, several ESD parameters were studied such as total salt concentration solution (0.05, 0.01 0.005 mol L−1), substrate (range from 275 350 °C), solvent composition (using different butyl-carbitol :...

Abstract One-photon up-conversion, also called anti-Stokes photoluminescence (ASPL), is the process whereby photoexcited carriers scavenge thermal energy and are promoted into a higher excited state before emitting photon of greater than initially absorbed. Here, we examine how ASPL from CsPbBr 3 nanoparticles modified by coupling with plasmonically active gold deposited on substrate. Two regimes examined using confocal fluorescence microscopy: three to four Au per diffraction limited region...

Optical properties of nanoparticle assemblies reflect the distinctive characteristics their building blocks and spatial organization, giving rise to emergent phenomena. Design functional like clusters superlattices has progressed through integrated experimental computational studies establishing principles connecting structure properties. However, conventional electromagnetic simulation methods are computationally expensive inadequate for treating more complex assemblies, such as gels mixed...

Gelation offers a powerful strategy to assemble plasmonic nanocrystal networks incorporating both distinctive optical properties of constituent building blocks and customizable collective properties. Beyond what single-component assembly can offer, characteristics be tuned in broader range when two or more components are intimately combined. Here, we demonstrate mixed gel using thermoresponsive metal-terpyridine links that enable rapid disassembly with thermal cycling. Plasmonic indium oxide...