- Nano Idea
- Open Access
Fabrication of inverted zinc oxide photonic crystal using sol–gel solution by spin coating method
© Huang et al.; licensee Springer. 2013
Received: 4 March 2013
Accepted: 20 April 2013
Published: 2 July 2013
Inverted zinc oxide photonic crystal structures were fabricated from polystyrene sphere (PSS) template using the sol–gel solution of ZnO by spin-coating method. It is easily able to control and fabricate the photonic crystal structures using the self-organized PSS with a size of 193 nm. The inverted ZnO photonic crystal structures observed show the (111) tendency of the hexagonal compact arrangement formation. The resulting structures possess the photonic band gaps in the near-ultraviolet range and exhibit an enhanced photoluminescence spectrum. The technology can effectively increase the light output intensity or efficiency for the applications of optoelectronic devices.
Since photonic crystals (PhCs) were first proposed in 1987 by Yablonovitch  and John , they have been studied with great interest as a means of localizing light and modifying the emission properties of embedded light sources . Material infiltration of three-dimensional (3D) polystyrene sphere (PSS) PhC has been a versatile method to fabricate the so-called inverted structure, which has long-range order, high filling fraction, and refractive index contrast required to exhibit a photonic band gap. Infiltration has been recently achieved by various methods, including chemical bath deposition , electrodeposition , and low-pressure chemical vapor deposition . To achieve both high filling fractions and good luminescence properties of this material has been proven difficult . In spite of the few studies regarding the sol–gel method, this method has some advantages, such as the easy control of chemical components and fabrication of thin film at low cost to investigate the structural and optical properties of ZnO thin films. Several groups have, therefore, studied the emission properties of lasing dyes or quantum dots infiltrated into inverted opal backbones . Teh et al. reported that the optical gain of the 3D ZnO inverse opal fabricated by electrodeposition is further enhanced due to the localized defect modes within the primary photonic pseudogap. Teh et al. reported the room-temperature ultraviolet lasing and the mechanisms of lasing modes in 3D ZnO inverse opals fabricated via colloidal templating with electrochemical infiltration. They further investigated the mechanisms of lasing modes and deduced that periodic structures would facilitate strain-induced change in lasing energy and provide modulation in refractive index for enhanced light confinement as well as optical feedback. They concluded that the periodic photonic structure plays a role, i.e., the modulation in refractive index would enhance the light confinement as well as the optical feedback . The inverted ZnO PhC possesses a wide electronic band gap (3.2 eV at room temperature) and high exciton binding energy (60 meV), which makes it an efficient short-wavelength light source in the near ultra-violet (NUV) spectrum. Its refractive index (2.26) is too low to produce a full (i.e., omnidirectional) photonic band gap but sufficient for the formation of directional pseudogaps. In this article, we report the fabrication of inverted ZnO PhC using sol–gel solution by spin coating method and demonstrate the morphology, reflection spectra, and luminescence in the NUV region for the examination of the process on inverted ZnO PhCs.
Summary and conclusions
We have successfully fabricated the inverted ZnO PhC structure using the sol–gel solution of ZnO by spin coating method. Sol–gel is capable of producing high filling fraction inverted opal materials with very good crystalline quality. The results of the inverted ZnO structure exhibit clear strong NUV photoluminescence at the wavelength of 378 nm, which makes them interesting candidates for studying the characteristics of modified spontaneous and stimulated emission in active ZnO PhCs. The combination of aqueous chemical growth and nanosphere lithography is expected to provide a facile, large-scale, and low-cost fabrication method at low temperatures, which shall be of significant value for practical applications of the grown PhCs.
The financial support from National Science Council (101-2218-E-007-007 and 100-2221-E-007-084-MY3) is deeply appreciated.
- Yablonovitch E: Inhibited spontaneous emission in solid-state and electronics. Phys Rev Lett 1987, 58: 2059–2062. 10.1103/PhysRevLett.58.2059View ArticleGoogle Scholar
- John S: Strong localization of photons in certain disordered dielectric superlattices. Phys Rev Lett 1987, 58: 2486–2489. 10.1103/PhysRevLett.58.2486View ArticleGoogle Scholar
- Shkunov MN, Vardeny ZV, DeLong MC, Polson RC, Zakhidov AA, Baughman R: Tunable, gap-state lasing in switchable directions for opal photonic crystals. Adv Funct Mater 2002, 12: 21–26. 10.1002/1616-3028(20020101)12:1<21::AID-ADFM21>3.0.CO;2-SView ArticleGoogle Scholar
- Wijnhoven JEGJ, Bechger L, Vos WL: Fabrication and characteristics of large macroporous photonic crystals in titania. Chem Mater 2001, 13: 4486–4499. 10.1021/cm0111581View ArticleGoogle Scholar
- Braun P, Zehner RW, White CA, Weldon MK, Kloc C, Patel SS, Wiltzius P: Epitaxial growth of high dielectric contrast three-dimensional photonic crystals. Adv Mater 2001, 13: 721–724. 10.1002/1521-4095(200105)13:10<721::AID-ADMA721>3.0.CO;2-AView ArticleGoogle Scholar
- Meseguer F, Blanco A, Miguez H, Santamaria FG, Ibisate M, Lopez C: Synthesis of inverse opals. Colloids Surf A 2002, 202: 281–290. 10.1016/S0927-7757(01)01084-6View ArticleGoogle Scholar
- Lopez C: Materials aspects of photonic crystals. Adv Mater 2003, 15: 1679–1704. 10.1002/adma.200300386View ArticleGoogle Scholar
- Koenderink AF, Bechger L, Lagendijk A, Vos W: An experimental study of strongly modified emission in inverse opal photonic crystals. Phys Status Solidi A 2003, 197: 648–661. 10.1002/pssa.200303115View ArticleGoogle Scholar
- Teh LK, Wong CC, Yang HY, Lau SP, Yu SF: Lasing in electrodeposited ZnO inverse opal. Appl Phys Lett 2007, 91: 1611116–1611118.View ArticleGoogle Scholar
- Gruber JB, Reynolds TA, Alekel T, Sardar DK, Zandi B, Keszler D: Spectra and energy levels of Co2+ in zinc oxide metaborate. Phys Rev B 2001, 64: 045111–045117.View ArticleGoogle Scholar
- Kedia S, Vijayaa R, Rayb AK, Sinhab S: Photonic stop band effect in ZnO inverse photonic crystal. Opt Mater 2011, 33: 466–474. 10.1016/j.optmat.2010.10.020View ArticleGoogle Scholar
- Emelchenko GA, Gruzintsev AN, Masalov VV, Samarov EN, Bazhenov AV, Yakimov EE: ZnO-infiltrated opal: influence of the stop-zone on the UV spontaneous emission. J Opt A: Pure Appl Opt 2005, 7: S213-S218. 10.1088/1464-4258/7/2/028View ArticleGoogle Scholar
- Yang Y, Yan H, Fu Z, Yang B, Zuo J, Fu S: Enhanced photoluminescence from three dimensional ZnO photonic crystals. Solid State Commun 2006, 139: 218–221. 10.1016/j.ssc.2006.06.003View ArticleGoogle Scholar
- Kumagai M, Toshihide T: Excitonic and nonlinear-optical properties of dielectric quantum-well structures. Phys Rev B 1989, 40: 12359–12381. 10.1103/PhysRevB.40.12359View ArticleGoogle Scholar
- Muljarov EA, Zhukov EA, Dneprovskii VS, Masumoto Y: Dielectrically enhanced excitons in semiconductor-insulator quantum wires: theory and experiment. Phys Rev B 2000, 62: 7420–7432. 10.1103/PhysRevB.62.7420View ArticleGoogle Scholar
- Baryshev AV, Khanikaev AB, Fujikawa R, Uchida H, Inoue M: Polarized light coupling to thin silica-air opal films grown by vertical deposition. Phys Rev B 2007, 76: 0143051–0143059.Google Scholar
- Yang Y, Yang B, Fu Z, Yan H, Zhen W, Dong W, Xia L, Liu W, Jian Z, Li F: Enhanced yellow-green photoluminescence from ZnO-SiO2 composite opal. J Phys Condens Matter 2004, 16: 7277–7286. 10.1088/0953-8984/16/41/009View ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.