Hybrid materials (HM) based on organic-inorganic substances are of a great interest due to specific properties of nanosize particles disordered or ordered into matrix. Organic luminescent materials demonstrate high efficiency both at optical and electric current excitation. But, in general, most of organic phosphors are unstable at room atmosphere and need to be protected. Incorporation of organic materials into transparent inorganic matrix could solve the problem of degradation and give an opportunity to get new materials with unique properties.

In the recent 15th years a lot of studies of HM's delt with an inorganic matrix, which based on glasses [1,2], silicon oxide nanospheres [3,4], thin amorphous films [5,6], xerogels [7,8], layered double hydroxides [9], single crystals [10,11].

HM's were synthesized by variations of sol-gel technique [1-9], single crystal based HM's [10,11] were grown from solutions. An application of these techniques results to incorporation of OH–group in HM's and correspondingly to luminescence quenching at the OH–group oscillations. Synthesis of new efficient phosphors based on organic metal-complex compounds with high decay temperature (higher 300 °C) makes possible a synthesis of hybrid optic materials using glass melt technology. In this case we could decrease the energy dispersion on residual anion groups.

In the present research we used low-melting borate glasses (B₂O₃, Na₂O-B₂O₃, PbF₂-B₂O₃) as a glass matrix and organic phosphor was a metal complex of Me³⁺ (Al, In) with 8-quinolinol (tris-(8-hydroxyquinoline) aluminum, Alq₃ and tris-(8-hydroxyquinoline) indium, Inq₃). They are stable up to 450°C melting temperature.

Meq₃ molecules exist as two geometrical isomers: meridianal and facial (mer- and fac-), and crystallized in some polymorphs (mer- in α-, β- ε-phase, fac- in γ-, δ-phase) [9, 12]. Meq₃ luminescent properties depend on the central metal ion, polymorph, and isomer.  

Metal complexes were synthesized by the reaction:

3 C₉H₇ON + Me⁺³+3OH^–  =  (C₉H₆ON)₃ Me + 3 H₂O

The synthesis was conducted during 1 hour at 25°C, continuous mixing, pH=10. The purification procedure included two stages. At the first stage impurities were extracted into hexane. At the second stage metal complexes was sublimated in vacuum under p<10^-5 Torr at stepped heating to 90→200→250→290°C and 1.5 hours exposure at the very temperature.

HM's were synthesized by melting of a mixture of 0.02-0.1 wt. % Meq₃ in dried B₂O₃ powder at temperatures below the decay temperature during 10-60 minutes. Glass samples were obtained by the melt freezing or thick thread pulling.

Hybrid samples were transparent in 250 – 2700 nm range and did not content visible inclusions and bulbs. The influence of glass melting parameters on HM's structure and spectral properties was studied.

We found out that in case of Alq₃ (Fig.) that an increase of synthesis duration resulted in linear shift of chromaticity coordinates according to the equation Y = 4.1093·X – 0.4859 from green (dot 1) to blue (dot 5) with corresponding changes luminescent maximum peak from 513 nm for pure Alq₃ to 443 nm for HM with maximum melting duration. Dots 1-5 forms the GB edge of the RGB triangle for full-color emitting devices using only Alq₃ as a luminophor component. This is perspective for development of new classes of emitting devices based on hybrid materials

 Fig. Chromaticity diagram (CIE) with marks corresponding to samples X-Y color coordinates: 1 – original Alq₃; 2 – 5 –  Alq₃/B₂O₃ – hybrid materials, melted at: 2 – 400 ^оС, 8 min, 3 – 400 ^оС, 10 min; 4 – 390 ^оС, 30 min; 5 – 400 ^оС, 60 min

1. N.Sanza, P.L. Baldeckb, A. Ibane.// Synthetic Metals. V.115. 2000. p. 229-234
2. P. Innocenzi, A. Martucci, M. Guglielmi, L. Armela // Journal of Non-Crystalline Solids. 1999. Vol. 259. P. 182-190
3. D. Zhao, W. Qin, C. Wu, J. Zhang, G. Qin, H. Lin // Journal of Rare Earths. 2004. V. 22.№ 1. p. 49-52
4. C. Huang, T Sun, W. Tian, B. Zhao // Journal of Rare Earths. 2006. V. 24, № 2, p. 134-137
5. X. Hao, X. Fan, M. Wang. // Thin Solid Films.V. 353. 1999. № 1-2, p. 223-226
6. D. Bersani, P.P. Lottici, M. Casalboni, P. Prosposito// Materials Letters. V. 51. 2001. p. 208–212
7. L.D. Carlos, R.A. Sa Ferreira, V. de Zea Bermudez // Electrochimica Acta. V. 45. 2000. p. 1555–1560
8. X. Fan, Z. Wang, M. Wang // Journal of Luminescence.V. 99, 2002. № 3, p. 247-254
9. S. Li, J. Lu, M. Wei, D.G. Evans, X. Duan. // Adv. Funct. Mater. V. 20. 2010. p. 2848–2856
10.T. Watanabe, N. Doki, M. Yokota, K. Shimizu// Mat. APCChE 2010, October 5-8, 2010, Taipei
11. I. Pritula, V. Gayvoronsky, Yu. Gromov, at all // Optics Communications. V. 282. 2009. № 6, p. 1141-1147
12. I. Hernandez and W P. Gillin // J. Phys. Chem. B, V. 113, 2009. p. 14079–14086

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/28768 must be provided.

1. Czochralski grown large diameter Li₂MoO₄ single crystals
2. Optimization of vibrating baffle configuration at AVC-CZ crystal growth
3. Impurity Influence On Polytype Generation At SiC Vapor Growth
4. Nonstoichiometry and optical properties of ZnSe crystal grown from melt and vapor
5. Czochralski growth of NaNO₃-LiNO₃ solid solution single crystals using axial vibrational control technique
6. VGF Growth of CdTe Crystal Assisted by Axial Vibration Control  Technique Under Controlled Cadmium Pressure
7. Nonstoichiometry of ZnTe and CdTe vapor grown crystals