Yogendra K. Gautam

Influence of Sputtering Gas on Morphological and Optical Properties of Magnesium Films

Abstract The influence of sputtering gas (He & Ar) on the structural properties of Mg thin films has been investigated. The optical property (reflectance) that results from the growth of films at varying substrate temperatures ( T sub ) was also studied. The deposited films were characterized by using X-ray diffraction (XRD), field emission scaning electron microscopy (FE-SEM), atomic force microscopy (AFM) and UV-Vis-NIR spectrophotometer. The smaller crystallite size and lower deposition rate were observed in the presence of Helium atmosphere compared to Argon. Morphology of the films shows 2D hexagonal geometry of grains in the deposition temperature range ( T sub ≈50–150°C) in both the sputtering gases. The surface roughness of the polycrystalline films were found to increase with increase in the deposition temperature of both ambient gases. Optical reflectance of Mg films was measured in near infrared region and larger reflectance was observed from Mg films sputtered in He atmosphere compared to that in argon.

Effect of Working Pressure on Structural, Electrical and Optical Properties of CIGS Thin Film Deposited by PLD

CuIn0.8Ga0.2Se2 (CIGS) thin films have been successfully deposited on soda lime glass substrate at different working (Ar gas) pressures by Pulsed laser deposition (PLD). The effect of working pressure on the structural, electrical and optical properties of CIGS thin films has been investigated. All deposited CIGS thin films are found to be polycrystalline in nature with preferred orientation along (112). Crystallinity of CIGS thin films has been improved with decreasing of working pressures in PLD chamber. Stoichiometry of CIGS thin films has been maintained for all working pressures. Optical transmittance and electrical sheet resistance of CIGS thin films have been found to decrease with decrease of working pressure. The results of the present study signify that desired structural, electrical and optical properties of CIGS thin films can be obtained by changing the processing parameter in PLD method.Keywords: CIGS, XRD, Stoichiometry, UV-Vis-NIR spectrophotometer.

Thickness dependent structural, optical and electrical properties of CuIn0.8Ga0.2Se2 thin films deposited by pulsed laser deposition

CuIn0.8Ga0.2Se2 (CIGS) polycrystalline thin films have been deposited on soda lime glass substrate at different deposition time by pulsed laser deposition. The effect of thickness on structural, surface morphological, optical and electrical properties of thin films were investigated by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), UV-Vis-NIR spectrophotometer and electrical measurement unit. XRD study reveals that all deposited films are polycrystalline in nature and have tetragonal phase of CIGS. Crystallinity of CIGS films has been found to improve with increase in thickness of CIGS films as evidenced by sharp XRD peaks for (112) orientation. Grain size and rms surface roughness of CIGS films have been found to be increased with increase in thickness. All the deposited CIGS films exhibit direct band gap semiconducting behaviour with ∼106 cm−1 absorption co-efficient. Optical band gap and resistivity of CIGS films have been found to decre...

Study on structural, optical and wettable properties of CeO2 thin films deposited by reactive DC magnetron sputtering

CeO2 thin films have been deposited on different substrates (Si & quartz) by reactive DC magnetron sputtering technique and effect of target-substrate distance (dT-S) on structural, optical, and wettable properties has been investigated. XRD data reveals that CeO2 films are polycrystalline in nature with cubic structure. Variation in growth rates of different orientations with change in dT-S has been observed. Evolution of (200) peak for the film deposited on Si substrate confirms the substrate dependence of the texture. Surface morphology of the films has been characterized by AFM. Wettability and optical properties have been studied using contact angle goniometer and UV-Vis spectrophotometer, respectively. CeO2 films deposited at 5 cm dT-S have least transmittacnce but highest hydrophobicity among all the studied samples.