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Jiménez-Villar E, Martins WS, Wetter NU. Ordered photonic colloidal suspensions. APPLIED OPTICS 2023; 62:2707-2710. [PMID: 37133109 DOI: 10.1364/ao.477410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ordered photonic structures (photonic crystals) have seen increasing interest in recent years due to their potential applications, which depend on fabrication technologies suitable for mass production. In this paper, we studied by light diffraction the order in photonic colloidal suspensions composed by core-shell (T i O 2@S i l i c a) nanoparticles suspended in ethanol and water solutions. Light diffraction measurements show order in these photonic colloidal suspensions, being stronger in ethanol compared with suspensions in water. Strong and long-range Coulomb interaction explains the order and correlation in the scatterers' (T i O 2@S i l i c a) position, which favors significantly the interferential processes as localization of light.
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Zhou L, Liu S, Zhong T. A comprehensive review of optical diffusers: progress and prospects. NANOSCALE 2023; 15:1484-1492. [PMID: 36594788 DOI: 10.1039/d2nr04579f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Optical diffusers made of polymer composite materials are vital for many photonic and optoelectronic applictions such as backlight unit (BLU) in liquid crystal displays (LCDs), light extraction unit of organic light emitting diodes (OLEDs), and solar cells. We have described the types of optical diffusers, the theory and measurement of light scattering, some common approaches for fabricating optical diffusers, the potential applications and recent developments of optical diffusers containing optical physical unclonable functions (PUFs), optical random number generators, passive stretchable radiative coolers, diffuser -based deep neural networks, lensless cameras or imaging systems, and three dimensinonal (3D) displays including two dimensional (2D)/3D switchable displays, which provide effective ways for designing high-performance optical films in the applications of optical devices. To satisfy the requirements for applications in stretchable optoelectronics and optomechanics, tunable optical diffusers stimulated by electric field, heat, light, mechanical field, or ultrasound attract much attention. Polymer/liquid crystal (LC) composite films with tunable light transmittance, haze, and diffusing intensity have been firstly provided and set a great foundation for the next generation of flexible and switchable optical diffusers.
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Affiliation(s)
- Le Zhou
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China.
| | - Sijie Liu
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China.
| | - Tingjun Zhong
- Department of Chemistry, College of Science, China Agricultural University, Beijing 100083, P. R. China.
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Ermakov VA, Martins WS, Wetter NU, Marques FC, Jiménez-Villar E. Localization of light induced in ordered colloidal suspensions: powerful sensing tools. NANOSCALE 2021; 13:6417-6425. [PMID: 33585851 DOI: 10.1039/d0nr08736j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We study the light-matter coupling by Raman scattering in colloidal suspensions composed by core-shell TiO2@Silica (Rutile@Silica) nanoparticles suspended in ethanol and water solutions. Strong enhancement of the Raman signal per particle is observed as [TiO2@Silica] is increased above a threshold, being stronger in ethanol suspensions. Moreover, above this [TiO2@Silica] threshold, the optical transmittance of the ethanol suspension starts to be considerably lower than in water, despite scattering strength being higher in water. These results are attributed to localization of light induced by strong correlation in the scatterers' position as a consequence of the long-range Coulomb interaction between the TiO2@Silica nanoparticles. Light diffraction in TiO2@Silica suspensions (water and ethanol) shows strong correlation in the scatterers' position (structure seemingly cubic), being stronger in ethanol than in water (longer-range Coulomb interaction). As a result, we demonstrate in these colloidal suspensions for the first time, to our knowledge, strongly enhanced light-matter coupling through correlation-induced localization with klT much higher than unity and in an ordered colloidal-photonic structure. This strong enhancement of light-matter coupling by localization of light opens an avenue for manufacturing powerful sensing tools.
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Affiliation(s)
- Viktor A Ermakov
- Departamento de Física, Universidade Federal de São Carlos, São Carlos, SP 13565-905, Brazil
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Ermakov VA, Silva Filho JMD, Bonato LG, Mogili NVV, Montoro FE, Iikawa F, Nogueira AF, Cesar CL, Jiménez-Villar E, Marques FC. Three-Dimensional Superlattice of PbS Quantum Dots in Flakes. ACS OMEGA 2018; 3:2027-2032. [PMID: 31458511 PMCID: PMC6641286 DOI: 10.1021/acsomega.7b01791] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/07/2018] [Indexed: 05/20/2023]
Abstract
In the last two decades, many experiments were conducted in self-organization of nanocrystals into two- and three-dimensional (3D) superlattices and the superlattices were synthesized and characterized by different techniques, revealing their unusual properties. Among all characterization techniques, X-ray diffraction (XRD) is the one that has allowed the confirmation of the 3D superlattice formation due to the presence of sharp and intense diffraction peaks. In this work, we study self-organized superlattices of quantum dots of PbS prepared by dropping a monodispersed colloidal solution on a glass substrate at different temperatures. We showed that the intensity of the low-angle XRD peaks depends strongly on the drying time (substrate temperature). We claim that the peaks are originated from the 3D superlattice. Scanning electron microscopy images show that this 3D superlattice (PbS quantum dots) is formed in flake's shape, parallel to the substrate surface and randomly oriented in the perpendicular planes.
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Affiliation(s)
- Viktor A. Ermakov
- Universidade
Estadual de Campinas, IFGW, Campinas, São Paulo 13083-859, Brazil
- E-mail:
| | | | - Luiz Gustavo Bonato
- Universidade
Estadual de Campinas, IQ, Campinas, São Paulo 13083-861, Brazil
| | | | | | - Fernando Iikawa
- Universidade
Estadual de Campinas, IFGW, Campinas, São Paulo 13083-859, Brazil
| | - Ana Flavia Nogueira
- Universidade
Estadual de Campinas, IQ, Campinas, São Paulo 13083-861, Brazil
| | - Carlos Lenz Cesar
- Universidade
Estadual de Campinas, IFGW, Campinas, São Paulo 13083-859, Brazil
- Universidade
Federal do Ceará, DF, Fortaleza, Ceará 60440-900, Brazil
| | - Ernesto Jiménez-Villar
- Universidade
Estadual de Campinas, IFGW, Campinas, São Paulo 13083-859, Brazil
- Instituto
de Pesquisas Energéticas e Nucleares, CNEN, São Paulo, São Paulo 05508-000, Brazil
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Wetter NU, Ramos de Miranda A, Pecoraro É, Lima Ribeiro SJ, Jimenez-Villar E. Dynamic random lasing in silica aerogel doped with rhodamine 6G. RSC Adv 2018; 8:29678-29685. [PMID: 35547269 PMCID: PMC9085255 DOI: 10.1039/c8ra04561e] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/22/2018] [Accepted: 08/13/2018] [Indexed: 11/30/2022] Open
Abstract
Silica aerogel is a lightweight material, well known for its good mechanical and thermal characteristics, but its optical properties have received less attention, because it is weakly scattering. Here we present for the first time the lasing properties and their complex dynamics of silica aerogel doped with R6G. It is shown that the Q factors of the lasing modes determine the operation of the laser, being either resonant or ASE-lasing. For resonant lasing, the number of resonators is easily varied and the number of modes in a single resonator and their emission frequency can be dynamically adjusted, making this a truly versatile photonics material. We demonstrate dynamically adjustable resonant lasing in silica aerogel, which makes this a truly versatile photonics material.![]()
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Affiliation(s)
| | | | - Édison Pecoraro
- Instituto de Química de Araraquara
- Universidade Estadual Paulista Júlio de Mesquita Filho
- Araraquara
- Brazil
| | - Sidney José Lima Ribeiro
- Instituto de Química de Araraquara
- Universidade Estadual Paulista Júlio de Mesquita Filho
- Araraquara
- Brazil
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Assisted laser ablation: silver/gold nanostructures coated with silica. APPLIED NANOSCIENCE 2017. [DOI: 10.1007/s13204-017-0599-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Jiménez-Villar E, da Silva IF, Mestre V, Wetter NU, Lopez C, de Oliveira PC, Faustino WM, de Sá GF. Random Lasing at Localization Transition in a Colloidal Suspension (TiO 2@Silica). ACS OMEGA 2017; 2:2415-2421. [PMID: 31457590 PMCID: PMC6641038 DOI: 10.1021/acsomega.7b00086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/20/2017] [Indexed: 05/20/2023]
Abstract
Anderson localization of light and random lasing in this critical regime is an open research frontier, which besides being a basic research topic could also lead to important applications. This article investigates the random laser action at the localization transition in a strongly disordered scattering medium composed of a colloidal suspension of core-shell nanoparticles (TiO2@Silica) in ethanol solution of Rhodamine 6G. The classical superfluorescence band of the random laser was measured separately by collecting the emission at the back of the samples, showing a linear dependence with pumping fluence without gain depletion. However, frontal collection showed saturation of the absorption and emission. Narrow peaks of approximately equal intensity are observed on top of the classical superfluorescence band, indicating suppression of the interaction between the peaks modes. The linewidth of these peaks is lower than that of the passive modes of the scattering medium. A method called fraction of absorbed pumping allowed us to infer that this peak's mode (localized modes) is confined to a shallow region near the input-pumping border.
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Affiliation(s)
- Ernesto Jiménez-Villar
- Departamento
de Química Fundamental, Universidade
Federal de Pernambuco, Cidade Universitária, 50670-901 Recife, PE, Brazil
- E-mail:
| | - Iran F. da Silva
- Departamento de Química and Departamento de Física, Universidade Federal da Paraíba, Cidade Universitária, 58051-970 João Pessoa, PB, Brazil
| | - Valdeci Mestre
- Universidade
Estadual da Paraíba, CCEA, Rua Alfredo Lustosa Cabral, s/n, 58706-560 Patos, PB, Brazil
| | - Niklaus U. Wetter
- Instituto
de Pesquisas Energéticas e Nucleares, CNEN-IPEN, Rua Prof. Lineu Prestes 2242 −
Cidade Universitária, 05508-000 São Paulo, SP, Brazil
| | - Cefe Lopez
- Instituto
de Ciencia de Materiales de Madrid (CSIC), Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - Paulo C. de Oliveira
- Departamento de Química and Departamento de Física, Universidade Federal da Paraíba, Cidade Universitária, 58051-970 João Pessoa, PB, Brazil
| | - Wagner M. Faustino
- Departamento de Química and Departamento de Física, Universidade Federal da Paraíba, Cidade Universitária, 58051-970 João Pessoa, PB, Brazil
| | - Gilberto F. de Sá
- Departamento
de Química Fundamental, Universidade
Federal de Pernambuco, Cidade Universitária, 50670-901 Recife, PE, Brazil
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Ermakov VA, Jimenez-Villar E, Silva Filho JMCD, Yassitepe E, Mogili NVV, Iikawa F, de Sá GF, Cesar CL, Marques FC. Size Control of Silver-Core/Silica-Shell Nanoparticles Fabricated by Laser-Ablation-Assisted Chemical Reduction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:2257-2262. [PMID: 28186767 DOI: 10.1021/acs.langmuir.6b04308] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aqueous colloidal silver nanoparticles have substantial potential in biological application as markers and antibacterial agents and in surface-enhanced Raman spectroscopy applications. A simple method of fabrication and encapsulation into an inert shell is of great importance today to make their use ubiquitous. Here we show that colloids of silver-core/silica-shell nanoparticles can be easily fabricated by a laser-ablation-assisted chemical reduction method and their sizes can be tuned in the range of 2.5 to 6.3 nm by simply choosing a proper water-ethanol proportion. The produced silver nanoparticles possess a porous amorphous silica shell that increases the inertness and stability of colloids, which decreases their toxicity compared with those without silica. The presence of a thin 2 to 3 nm silica shell was proved by EDX mapping. The small sizes of nanoparticles achieved by this method were analyzed using optical techniques, and they show typical photoluminescence in the UV-vis range that shifts toward higher energies with decreasing size.
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Affiliation(s)
- Victor A Ermakov
- Universidade Estadual de Campinas, IFGW , Campinas, São Paulo 13083-859, Brazil
| | | | | | - Emre Yassitepe
- Universidade Estadual de Campinas, IQ , Campinas, São Paulo 13083-859, Brazil
| | | | - Fernando Iikawa
- Universidade Estadual de Campinas, IFGW , Campinas, São Paulo 13083-859, Brazil
| | | | - Carlos Lenz Cesar
- Universidade Estadual de Campinas, IFGW , Campinas, São Paulo 13083-859, Brazil
- Universidade Federal do Ceará, DF , Fortaleza, Ceará 60440-900, Brazil
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