Papers

ICMCTF2009 Session D3-1: Carbon and Nitrogen-Containing Nanostructured Composite and Nanolaminated Films

Wednesday, April 29, 2009 3:50 PM in Room Royal Palm 4-6

Wednesday Afternoon

Start	Invited?	Item
3:50 PM		D3-1-8 Applications of Nanocomposites in Organic Electronic Devices T.P. Nguyen (Institut des Materiaux Jean Rouxel, France); C.W. Lee (University of Chiao Tung, Taiwan) Organic electronic semiconductors have been developed over more than two decades and devices using them start to be commercialized in everyday applications. For instance, organic light emitting diodes (OLEDs) in small screens of cameras, cell phones, mp3 players or plastic photovoltaic cells (OPCs) cells are available on the market. Most of the materials used for these devices are conjugated polymers or small molecules, whose acute problem is their stability because degradation of materials affects the lifetime of devices. Among the different strategies proposed to remedy this drawback, the use of inorganic/organic nanocomposites is attractive by its easy processing and its ability to enhance the stability of the materials. In this talk, we present an overview of nanocomposites, which are commonly used in OLEDs and OPCs. The role of the inorganic parts, which are oxides or semiconductors, and its impact on the optical and electrical performance of devices, will be descr ibed and discussed. Some recent results on devices using nanocomposistesas active layers will be given as illustrations.
4:30 PM		D3-1-11 Cermet Structured a-c:H/Pt Thin Films as High Temperature Selective Solar Absorber Coatings Y.H. Lan, W.Y. Wu, J.M. Ting (National Cheng Kung University, Taiwan) Selective solar absorber coatings with a metal-dielectric composite structure attract great attentions due to the thermal stability at high operation temperature (>400°C). In this study, a-c:H/Pt solar absorber coatings exhibiting a double cermet structure were fabricated using a magnetron sputter deposition process. Amorphous hydrogenated carbon and platinum were used as the constituents as they provide high spectral selectivity and thermal stability. Thermal stability was tested by annealing the a-c:H/Pt solar absorber coatings at different temperature from 300 to 600°C in air. The as-deposited and heat treated samples were characterized using scanning electron microscopy, glazing incident X-ray diffraction, and transmission electron microscopy. The surface chemical state was investigated using X-ray photoelectron spectroscopy. The optical performance was also examined using UV-Vis-NIR spectrophotometry and IR spectrometry.
4:50 PM		D3-1-12 Microstructure and Mechanical Properties of CrAlN/Si₃N₄ Nanostructure Multilayered Coatings J.-G. Duh, S.-H. Tsao (National Tsing-Hua University, Taiwan) CrAlN and Si₃N₄ layers were deposited periodically by radio frequency reactive magnetron sputtering. In the CrAlN/Si₃N₄ multilayered coatings, the thickness of CrAlN layer was fixed at 4 nm, while the thickness of Si₃N₄ layer was adjusted from 4nm to 0.3nm. The dependence of the Si3N4 layer thickness on the preferred orientation, crystalline behavior and mechanical properties of multilayers coatings were discussed with the aid of XRD patterns and HRTEM. It was revealed that amorphous Si₃N₄ layer transformed to a crystallized one when the thickness decreased from 4nm to 0.3nm. The crystalline Si3N4 layer grew epitaxially and formed the coherent interface with the CrAlN layer and the column structure was exhibited. The critical layer thickness for the transition from amorphous Si₃N₄ to a crystallized one was 0.4nm, and maximum hardness of 33GPa was revealed.
5:10 PM		D3-1-10 Sol Gel Derived Hybrid Dielectric Thin films for ULSI Applications A.M. Mahajan, B.N. Joshi (North Maharashtra University, India) The hybrid materials with combine properties of organic and inorganic materials have attracted much attention.The number of precursors for inorganic component as metal alkoxides, organosilanes are available and they are compatible to incorporate polymerizable organic groups such as methycryloxy, vinyl and epoxy to yield wide variety of sol gel derived materials. Compare to inorganic sol gel derived hybrid films provides several advantages like better adhesion, transparency, flexibility and reduced surface roughness. These hybrid films have promising applications in optical devices, microelectronics, membranes, scratch resistant coatings etc. An important challenge for preparation of hybrid materials is to control the phase separation between the inorganic and organic moieties. In present paper, deposition of hybrid thin films of Polymer MethylMethAcrylate (PMMA)/ SiO₂composite has been reported. These hybrid films were deposited by sol gel spin coating te chnique. Methyl MethAcrylate (MMA) monomer was polymerized by Benzoyl PerOxide (BPO) at 60°C using water bath. This polymerised MMA were further added to sol of Tetraethylorthosilicate (TEOS), ethanol, water, acid catalyst with molar ratio 1:2:3.8:0.05. This mixture was constantly stirred for 2 hours and observed to homogenous after the stirring time. This homogenous PMMA/SiO₂sol with optimized viscosity was coated on Si substrate at 3000 rpm for 30 seconds and then dried at 200°C for 1 hour. The films have been characterized by FTIR shows the presence of hydrogen bonding at 935, 3378 cm^-1which supports strong chemical bonding of PMMA/ SiO₂. The other peaks in FTIR spectra at 1071.6, 797.5, 432.39, 1729.6, 1632.5 related to Si-O-Si stretching, Si-O-Si bending, Si-O-Si rocking, C=O, C=C bonds respectively. These films have good adhesion with Si substrate. The effect of annealing temperature and detailed study of FTIR will be discus s ed in main manuscript.