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Item Effect of stirring rate of the electrolyte on properties of electrodeposted CdS layers(Springer US, 2016) Atapattu, H.Y.R.; de Silva, D.S.M.; Pathiratne, K.A.S.; Dharmadasa, I.M.CdS is the most matching window material available for the CdTe absorber layer of CdS/CdTe solar cells and electrodeposition is a promising technique adaptable for fabrication of thin films of CdS owing to its simplicity, low cost, scalability and manufacturability. The quality of electrodeposited thin film semiconductor layers depends significantly on the electrodeposition potential, concentrations of precursor salts, pH, temperature and the rate of stirring of the electrolyte. In this study, the attention was focused on the effect of “stirring rate of electrolyte” since it has not been studied in detail in the past, despite of its strong relation to the rate of mass transport towards the working electrode where the thin film semiconductors are electrodeposited. This study was carried out via electrodepositing of CdS thin layers on fluorine doped tin oxide conducting glass working electrodes at different rates of stirring of the electrolyte while keeping the rest of the electrodeposition parameters unchanged at a previously identified set of values. The morphological, electrical and optical properties of the CdS layers grown at different stirring rates were used to determine the effect of stirring rate on the quality of CdS layers. The study revealed that, a stirring rate in the range of 60–125 rpm which produced orderly flows in the electrolyte around the working electrode (1 × 3 cm2) placed at the center of a 100 ml electrolytic bath with a distance of 2 cm apart between the graphite counter electrode and the conducting glass electrode could produce good quality CdS layers when electrodeposition was carried out at a cathodic deposition potential of 660 mV with respect to the saturated calomel electrode. The concentrations of CdCl2 and Na2S2O3 in the bath used were 0.10 and 0.01 M respectively. The temperature and pH of it were 60 °C and 1.80 respectively.Item Electrodeposition and Characterisation of CuInSe2 for applications in thin film solar cells(Thin Solid Films, 2001) de Silva, K.T.L.; Priyantha, W.A.A.; Jayanetti, J.K.D.S.; Chithrani, B.D.; Siripala, W.; Blake, K.; Dharmadasa, I.M.Copper indium diselenide (CuInSe2) layers have been grown at room temperature by electrochemical deposition technique in an aqueous medium. Resulting thin films have been characterised using XRD, XRF, XPS, GDOES and SEM for structural, stoichiometric and morphological properties. A considerable influence of the deposition potential on the atomic composition of In and Se present in the film was observed. Cu composition remains the same within the deposition potentials used in this investigation. The deposited layers are polycrystalline and annealing at 350�C for 30 min improves the crystallinity. The film quality deteriorates due to dissociation when annealed at temperatures above 350�C. Excessive annealing results in a surface which is depleted in Cu and rich in In and Se.Item Study of Annealing Effects of Cuprous Oxide Grown by Electrodepostion Technique(Solar Energy Materials and Solar Cells, 1996) Siripala, W.; Perera, L.D.R.D.; de Silva, K.T.L.; Jayanetti, J.K.D.S.; Dharmadasa, I.M.Low temperature electrochemical deposition of cuprous oxide from aqueous solutions has been investigated. X-ray diffraction, scanning electron microscopy, optical absorption, and photo-response of liquid/cuprous oxide junctions have been used to study the deposits' crystallographic, morphological, optical, and electrical properties. Effects of annealing in air have been studied using the above mentioned methods. As-deposited cuprous oxide exhibits a direct band gap of 2.0 eV, and shows an n-type behaviour when used in an liquid/solid junction. Annealing below 300�C enhances the n-type photocurrent produced by the junction. Type conversion occurs after heat treatments in air at temperatures above 300�C. No apparent bulk structure changes have been observed during annealing below this temperature, but heat treatments above this temperature produce darker films containing cupric oxide and its complexes with water.Item Study of annealing effects of cuprous oxide grown by electrodeposition technique(Solar Energy Materials and Solar Cells, 1996) Siripala, W.; Perera, L.D.R.D.; de Silva, K.T.L.; Jayanetti, J.K.D.S.; Dharmadasa, I.M.Low temperature electrochemical deposition of cuprous oxide from aqueous solutions has been investigated. X-ray diffraction, scanning electron microscopy, optical absorption, and photo-response of liquid/cuprous oxide junctions have been used to study the deposits' crystallographic, morphological, optical, and electrical properties. Effects of annealing in air have been studied using the above mentioned methods. As-deposited cuprous oxide exhibits a direct band gap of 2.0 eV, and shows an n-type behaviour when used in an liquid/solid junction. Annealing below 300�C enhances the n-type photocurrent produced by the junction. Type conversion occurs after heat treatments in air at temperatures above 300�C. No apparent bulk structure changes have been observed during annealing below this temperature, but heat treatments above this temperature produce darker films containing cupric oxide and its complexes with water.