Fig 1 - uploaded by Valery Grigorievich Golubev
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Cubic closed packed spheres of the opal structure: 1, SiO 2 sphere; 2, octahedral void; 3, tetrahedral void.
Source publication
In this study, three-dimensional ordered synthetic opals formed by spheres of 230 nm impregnated with GaN have been investigated. In some of the samples gold and platinum were also introduced. The poten-tial applications of GaN–opal assemblies include use in large surface area (of the order of 10 m2/cm3) GaN-based light-emitting devices at a high d...
Citations
Studies on a cubic Y2O3:Tb3+/SiO 2 inverse photonic lattice are reported. The method of preparation of the phosphor photonic lattice is described in detail. Scanning electron micrographs showed that the SiO2 spheres had an oxide coating of ~40 nm thickness in the final material. Optical micrographs of the final synthetic opal crystal infilled with cubic Y2O3:Tb3+ phosphor clearly show that the crystal rejected green light. It is shown that the crystal rejects green laser light but can be excited by 253.7 nm light, though the intensity of its green emission is strongly modulated by the presence of a stop-band at 559 nm (calculated by assuming complete filling of the voids in the template). Evidence is also presented to show that in such a photonic solid quenching of the luminescence does not take place at the same temperature as in the bulk solid.
Synthetic opals filled with CdTe exhibit a pronounced decrease of the intensity of photoluminescence for photon energies within the photonic band-gap. However, the intensity of emission increases much faster with the level of pumping inside the photonic band-gap than outside. It is argued that this behaviour can be explained if there is stimulated emission from photonic states in the photonic bandgap, which are strongly localized due to disorder. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
