Increasing Substrate Temperature (increasing + substrate_temperature)

Distribution by Scientific Domains

Selected Abstracts

Influence of substrate temperature on the properties of electron beam evaporated ZnSe films

M. G. Syed Basheer Ahamed
Abstract ZnSe films were deposited on glass substrates keeping the substrate temperatures, at room temperature (RT), 75, 150 and 250 C. The films have exhibited cubic structure oriented along the (111) direction. Both the crystallinity and the grain size increased with increasing deposition temperature. A very high value of absorption co-efficient (104 cm -1) is observed. The band gap values decrease from a value of 2.94 eV to 2.69 eV with increasing substrate temperature. The average refractive index value is in the range of 2.39 , 2.41 for the films deposited at different substrate temperatures. The conductivity values increases continuously with temperature. Laser Raman spectra showed peaks at 140.8 cm -1, 246.7 cm -1and 204.5 cm -1which are attributable to 2TA LO phonon and TO phonon respectively. ( 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Morphology control of GaN nanowires by vapor-liquid-solid growth

Y. Inoue
Abstract We synthesized GaN nanowires on sapphire substrate by metal organic chemical vapour deposition. The GaN nanowires were grown via vapor-liquid-solid (VLS) growth catalyzed with Ni thin film. Shape of nanowires depended on the substrate temperature and the growth pressure. The wire-like structure with high aspect ratio changed into the tapered structure with increasing substrate temperature, and with increasing the growth pressure. This dependency was attributed to the change of the surface diffusion length of source atoms. The VLS growth of GaN nanowire was revealed that the source species, absorbed at the eutectic droplet, came along the side wall of the nanowire as well as other semiconductor nanowires. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Deposition of copper-doped iron sulfide (CuxFe1,xS) thin films using aerosol-assisted chemical vapor deposition technique

Sujit D. Disale
Abstract Copper-doped iron sulfide (CuxFe1,xS, x = 0.010,0.180) thin films were deposited using a single-source precursor, Cu(LH)2Cl2 (LH = monoacetylferrocene thiosemicarbazone), by aerosol-assisted chemical vapor deposition technique. The Cu-doped FeS thin films were deposited at different substrate temperatures, i.e. 250, 300, 350, 400 and 450 C. The deposited thin films were characterized by X-ray diffraction (XRD) patterns, Raman spectra, scanning electron microscopy, energy dispersive X-ray analysis (EDX) and atomic force microscopy. XRD studies of Cu-doped FeS thin films at all the temperatures revealed formation of single-phase FeS structure. With increasing substrate temperature from 250 to 450 C, there was change in morphology from wafer-like to cylindrical plate-like. EDX analysis showed that the doping percentage of copper increased as the substrate temperature increased from 250 to 450 C. Raman data supports the doping of copper in FeS films. Copyright 2010 John Wiley & Sons, Ltd. [source]

Growth and Properties of TiCl4 -Derived CVD Titanium Oxide Films at Different CO2/H2 Inputs,

D.-H. Kuo
Abstract Crystalline titanium oxide films with a thickness of 0.09,0.55,,m were prepared at temperatures below 500,C by CVD using a mixture of titanium tetrachloride (TiCl4), carbon dioxide (CO2), and hydrogen (H2) as reactants. Film thickness decreased with increasing substrate temperature and CO2/H2 input. Nanosized microstructure was obtained at high CO2/H2 input due to the growth retardation of reacted HO-TiCl3* by the unreacted TiCl4 and CO2. That film composition, i.e., the O/Ti ratio, increased with temperature and the CO2/H2 input can be explained by growth kinetics. Unlike film thickness, internal film stress increased with increasing substrate temperature. Adhesion was controlled by compressive internal stress due to the weak bonding between film and substrate. Two growth mechanisms are proposed to explain the tensile and compressive stress states in films produced by CVD. The adsorption-controlled reaction has a film in compressive stress that increases with an increase in temperature. On the other hand, thermally activated CVD produces a film in tensile stress that decreases with an increase in substrate temperature. [source]