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Khatun N, Sridurai V, Nair GG. Towards complete photonic band gap in a high refractive index nanoparticle-doped blue phase liquid crystal. NANOSCALE 2023; 15:17808-17817. [PMID: 37661760 DOI: 10.1039/d3nr03366j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Three-dimensional (3D) photonic crystals with complete photonic band gap (PBG) are fascinating due to the possibility of controlling light in all directions. Realizing such photonic crystals is nontrivial due to symmetry requirements and associated fabrication challenges. Liquid crystalline cubic blue phases (BPs) are soft 3D photonic crystals with an incomplete PBG due to the low refractive index contrast (<0.1). The present work attempts to drive a cubic BP towards a complete PBG via a simple approach of high refractive index nanoparticle-doping. The photonic band diagrams and reflection spectra of the nanoparticle-doped BP simulated using the finite element method show an increased PBG width, a parameter that quantifies the complete PBG. The reflection spectra obtained from UV-Vis-NIR spectroscopy show an increase (by a factor of >2) in PBG width for the nanoparticle-doped BP, validating the simulations. The findings are explained based on increased refractive index contrast (∼1.4) due to the nanoparticles getting trapped in the cores of disclination lines that make up the BP lattice. The simulations also indicate effective confinement of electric field eigenmodes in the nanoparticle-doped BP leading to high attenuation of the incident light. Further, the iso-frequency contours extracted from the band diagrams exhibit self-collimation and negative refraction of light.
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Affiliation(s)
- Nurjahan Khatun
- Centre for Nano and Soft Matter Sciences, Bangalore 562162, India.
- Manipal Academy of Higher Education, Manipal 576104, India
| | - Vimala Sridurai
- Centre for Nano and Soft Matter Sciences, Bangalore 562162, India.
| | - Geetha G Nair
- Centre for Nano and Soft Matter Sciences, Bangalore 562162, India.
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Orzechowski K, Tupikowska M, Strzeżysz O, Feng TM, Chen WY, Wu LY, Wang CT, Otón E, Wójcik MM, Bagiński M, Lesiak P, Lewandowski W, Woliński TR. Achiral Nanoparticle-Enhanced Chiral Twist and Thermal Stability of Blue Phase Liquid Crystals. ACS NANO 2022; 16:20577-20588. [PMID: 36475617 PMCID: PMC9798865 DOI: 10.1021/acsnano.2c07321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Blue phase liquid crystals (BPLCs) are chiral mesophases with 3D order, which makes them a promising template for doping nanoparticles (NPs), yielding tunable nanomaterials attractive for microlasers and numerous microsensor applications. However, doping NPs to BPLCs causes BP lattice extension, which translates to elongation of operating wavelengths of light reflection. Here, it is demonstrated that small (2.4 nm diameter) achiral gold (Au) NPs decorated with designed LC-like ligands can enhance the chiral twist of BPLCs (i.e., reduce cell size of the single BP unit up to ∼14% and ∼7% for BPI and BPII, respectively), translating to a blue-shift of Bragg reflection. Doping NPs also significantly increases the thermal stability of BPs from 5.5 °C (for undoped BPLC) up to 22.8 °C (for doped BPLC). In line with our expectations, both effects are saturated, and their magnitude depends on the concentration of investigated nanodopants as well the BP phase type. Our research highlights the critical role of functionalization of Au NPs on the phase sequence of BPLCs. We show that inappropriate selection of surface ligands can destabilize BPs. Our BPLC and Au NPs are photochemically stable and exhibit great miscibility, preventing NP aggregation in the BPLC matrix over the long term. We believe that our findings will improve the fabrication of advanced nanomaterials into 3D periodic soft photonic structures.
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Affiliation(s)
- Kamil Orzechowski
- Faculty
of Physics, Warsaw University of Technology, Koszykowa 75, 00-662Warsaw, Poland
| | - Martyna Tupikowska
- Faculty
of Chemistry, University of Warsaw, Pasteura 1, 02-093Warsaw, Poland
| | - Olga Strzeżysz
- Institute
of Chemistry, Military University of Technology, Kaliskiego 2, 00-908Warsaw, Poland
| | - Ting-Mao Feng
- Department
of Photonics, National Sun Yat-sen University, No. 70 Lien-hai Road, Kaohsiung80424, Taiwan
| | - Wei-Yuan Chen
- Department
of Photonics, National Sun Yat-sen University, No. 70 Lien-hai Road, Kaohsiung80424, Taiwan
| | - Liang-Ying Wu
- Department
of Photonics, National Sun Yat-sen University, No. 70 Lien-hai Road, Kaohsiung80424, Taiwan
| | - Chun-Ta Wang
- Department
of Photonics, National Sun Yat-sen University, No. 70 Lien-hai Road, Kaohsiung80424, Taiwan
| | - Eva Otón
- Institute
of Applied Physics, Military University
of Technology, Kaliskiego 2, 00-908Warsaw, Poland
| | - Michał M. Wójcik
- Faculty
of Chemistry, University of Warsaw, Pasteura 1, 02-093Warsaw, Poland
| | - Maciej Bagiński
- Faculty
of Chemistry, University of Warsaw, Pasteura 1, 02-093Warsaw, Poland
| | - Piotr Lesiak
- Faculty
of Physics, Warsaw University of Technology, Koszykowa 75, 00-662Warsaw, Poland
| | - Wiktor Lewandowski
- Faculty
of Chemistry, University of Warsaw, Pasteura 1, 02-093Warsaw, Poland
| | - Tomasz R. Woliński
- Faculty
of Physics, Warsaw University of Technology, Koszykowa 75, 00-662Warsaw, Poland
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Optical Filters Based on Cholesteric, Blue and Sphere Mesophases. Polymers (Basel) 2022; 14:polym14224898. [PMID: 36433026 PMCID: PMC9694172 DOI: 10.3390/polym14224898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/02/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022] Open
Abstract
An optical filter is one of the indispensable devices in massive and high-speed communication, optical signal processing, and display. Twist-structure liquid crystals, cholesteric liquid crystals, blue-phase liquid crystals, and sphere-phase liquid crystals show potential application in optical filters originating from the periodic nanostructures. Wavelength and bandwidth tuning can be controlled via temperature, electric fields, light, angle, spatial control, and templating technology. In this review, we discuss the recent developments of twist-structure liquid crystal filters.
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Han ZY, Kun SQ, Kang JT, Jia YG. New (-)-menthol-based blue phase liquid crystals with different polar substituents in the terminal group: Synthesis, mesophase behaviors, and DFT calculations. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Khatun N, Sridurai V, Gupta RK, Nath S, Kanakala MB, Garain S, Achalkumar AS, Yelamaggad CV, Nair GG. Effect of Photonic Band Gap on Photoluminescence in a Dye-Doped Blue Phase Liquid Crystal. J Phys Chem B 2021; 125:11582-11590. [PMID: 34618451 DOI: 10.1021/acs.jpcb.1c07422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tunability of fluorescence intensity is an essential parameter for enhancing the versatility of devices like emissive displays and solar cells. Soft photonic crystals, with their tunable photonic band gap (PBG), are highly sought-after systems for such purposes. Here, we report modulation of photoluminescence (PL) intensity in a fluorescent dye-doped blue phase liquid crystal, a 3D soft photonic crystal. On cooling, from the isotropic fluid phase, the PL intensity gets enhanced due to the overlapping of the emission wavelength of the dye with the photonic band edge. However, the PL intensity decreases on the application of an electric field, despite both thermal and electric fields having a similar effect (red shift) on the PBG. The contrasting behavior of PL intensity, also observed in composites obtained by varying the dye and the chiral dopant (handedness), is discussed in terms of scattering pathways for the emitted photons. The time-resolved PL studies show a reduction in the lifetime of the excited species upon cooling, validating the thermal dependence of PL intensity modulation due to Purcell effect. The facile modulation of PL intensity in the dye-doped blue phase system makes it appealing from the point of view of high-performance photonic applications.
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Affiliation(s)
- Nurjahan Khatun
- Centre for Nano and Soft Matter Sciences, Shivanapura, Bangalore 562162, India.,Manipal Academy of Higher Education, Manipal 576104, India
| | - Vimala Sridurai
- Centre for Nano and Soft Matter Sciences, Shivanapura, Bangalore 562162, India
| | - Ravindra K Gupta
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki Prefecture 305-0044, Japan
| | - Subrata Nath
- University of Duisburg-Essen, Universitätsstraße 7, Essen 45141, Germany
| | - Madhu B Kanakala
- Centre for Nano and Soft Matter Sciences, Shivanapura, Bangalore 562162, India
| | - Swadhin Garain
- Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | | | | | - Geetha G Nair
- Centre for Nano and Soft Matter Sciences, Shivanapura, Bangalore 562162, India
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Yang Y, Wang L, Yang H, Li Q. 3D Chiral Photonic Nanostructures Based on Blue‐Phase Liquid Crystals. SMALL SCIENCE 2021. [DOI: 10.1002/smsc.202100007] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Yanzhao Yang
- School of Materials Science and Engineering Tianjin University Tianjin 300350 China
| | - Ling Wang
- School of Materials Science and Engineering Tianjin University Tianjin 300350 China
| | - Huai Yang
- Department of Materials Science and Engineering College of Engineering Peking University Beijing 100871 China
| | - Quan Li
- Institute of Advanced Materials and School of Chemistry and Chemical Engineering Southeast University Nanjing 211189 China
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program Kent State University Kent OH 44242 USA
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