Nanostructure Formation Leading To Modify the Optical Absorption of Gaq3 Thin Films
This paper reports on the preparation of nanostructure along tris(8-hydroxyquinoline) gallium, Gaq3 thin film aiming at modifying its optical absorption property. The formation of nanostructure was achieved by means of thermal annealing in the temperature range from 85 oC to 255 oC under a flowing nitrogen gas for 10 minute. The results showed a modified optical absorption at 235 oC to produce a broad absorption spectrum which is quite wider than that of pristine film. It was noticed from the results of x-ray diffraction, XRD and field emission scanning electron microscopy, FESEM techniques that such annealing process has led to the formation of amorphous nanorods at specific temperatures, thereby modulating the films optical absorption. The relatively decreased absorption intensity at 255 oC was attributed to the partial crystalline formation and degraded nanostructures due to hard heating. Finally, the nanostructure growth was seen to possess a unique feature in modifying the optical behaviours of the Gaq3 thin films.
Brinkmann, M., Gadret, G., Muccini, M., Taliani, C., Masciocchi, N., and Sironi, A. (2000). Correlation between Molecular Packing and Optical Properties in Different Crystalline Polymorphs and Amorphous Thin Films of mer-Tris(8-hydroxyquinoline)aluminum(III). Journal of the American Chemical Society, 122(21), 5147-5157.
Cho, C.-P., Yu, C.-Y., and Perng, T.-P. (2006). Growth of AlQ3 nanowires directly from amorphous thin film and nanoparticles. Nanotechnology, 17, 5506–5510.
Credo, G. M., Winn, D. L., and Buratto, S. K. (2001). Near-Field Scanning Optical Microscopy of Temperature- and Thickness-Dependent Morphology and Fluorescence in Alq3 Films. Chemistry of Materials, 13(4), 1258-1265.
Djurišić, A. B., Lau, T. W., Lam, L. S. M., and Chan, W. K. (2004). Influence of atmospheric exposure of tris (8-hydroxyquinoline) aluminum (Alq3): a photoluminescence and absorption study. Applied Physics A: Materials Science and Processing, 78(3), 375-380.
Gahungu, G., and Zhang, J. (2005). Molecular geometry, electronic structure and optical properties study of meridianal tris(8-hydroxyquinolinato)gallium(III) with ab initio and DFT methods. Journal of Molecular Structure: THEOCHEM, 755(1-3), 19-30.
Hernández, I., and Gillin, W. P. (2009). Influence of High Hydrostatic Pressure on Alq3, Gaq3, and Inq3 (q = 8-Hydroxyquinoline). The Journal of Physical Chemistry B, 113(43), 14079-14086.
Higginson, K. A., Zhang, X.-M., and Papadimitrakopoulos, F. (1998). Thermal and Morphological Effects on the Hydrolytic Stability of Aluminum Tris(8-hydroxyquinoline) (Alq3). Chemistry of Materials, 10(4), 1017-1020.
Kao, P.-C., Chu, S.-Y., Huang, H.-H., Tseng, Z.-L., and Chen, Y.-C. (2009). Improved efficiency of organic photovoltaic cells using tris (8-hydroxy-quinoline) aluminum as a doping material. Thin Solid Films, 517(17), 5301-5304.
Kumar, P., Sonia, Patel, R. K., Prakash, C., and Goel, T. C. (2008). Effect of substrates on phase formation in PMN-PT 68/32 thin films by sol–gel process. Materials Chemistry and Physics, 110(1), 7-10.
Lian, J.-r., Yuan, Y.-b., Cao, L.-f., Zhang, J., Pang, H.-q., Zhou, Y.-f., et al. (2007). Improved efficiency in OLEDs with a thin Alq3 interlayer. Journal of Luminescence, 122–123(0), 660-662.
Muhammad, F. F., Abdul Hapip, A. I., and Sulaiman, K. (2010). Study of optoelectronic energy bands and molecular energy levels of tris (8-hydroxyquinolinate) gallium and aluminum organometallic materials from their spectroscopic and electrochemical analysis. Journal of Organometallic Chemistry, 695(23), 2526-2531.
Singh, R., Kumar, J., Singh, R. K., Kaur, A., Sood, K. N., and Rastogi, R. C. (2005). Effect of thermal annealing on surface morphology and physical properties of poly(3-octylthiophene) films. Polymer, 46(21), 9126-9132.
Vivo, P., Jukola, J., Ojala, M., Chukharev, V., and Lemmetyinen, H. (2008). Influence of Alq3/Au cathode on stability and efficiency of a layered organic solar cell in air. Solar Energy Materials and Solar Cells, 92(11), 1416-1420.
Wang, L., Jiang, X., Zhang, Z., and Xu, S. (2000). Organic thin film electroluminescent devices using Gaq3 as emitting layers. Displays, 21(2-3), 47-49.
Yokoyama, D., Sakaguchi, A., Suzuki, M., and Adachi, C. (2009). Horizontal orientation of linear-shaped organic molecules having bulky substituents in neat and doped vacuum-deposited amorphous films. Organic Electronics, 10(1), 127-137.
Yu, Y.-W., Cho, C.-P., and Perng, T.-P. (2009). Crystalline Gaq3 Nanostructures: Preparation, Thermal Property and Spectroscopy Characterization. Nanoscale Res Lett, 4, 820–827.
Zhang, J., and Frenking, G. (2004). Quantum chemical analysis of the chemical bonds in Mq3 (M = AlIII, GaIII) as emitting material for OLED. Chemical Physics Letters, 394(1-3), 120-125.
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