Physics
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Item Spectral responses of electrodeposited cuprous oxide thin film electrodes(Natural Resources, Energy and Science Authority of Sri Lanka, 1995) Siripala, W.Item n-type electrical conductivity in cuprous oxide thin films(Natural Resources, Energy and Science Authority of Sri Lanka, 1988) Siripala, W.; Kumara, K.P.Electrodeposited cuprous oxide thin films were investigated to determine whether their electrical conductivity is n-type or p-type. The experimental results based on the measurements of thermoelectric e.m.f, sheet resistance, dark and light current-voltage characteristics of Cu2O/CuxS and Cu2O/CuCNS heterojunctions reveal that the electrodeposited cuprous oxide films produce n-type electrical conductivity. These observations are in very good agreement with the previously reported n-type behavior of the electro-deposited Cu2O film electrodes in a photo-electrochemical cell.Item ITO/n-Cu2O/p-CuxS Thin Film Solar Cell(Sri Lanka Association for the Advancement of Science, 1997) Perera, L.D.R.D.; Wijesundera, R.P.; Siripala, W.; Jayasuriya, K.D.; de Silva, K.T.L.; Jayanetti, J.K.D.S.Item Ozone Production by Pulsed power in Dry Air(12th IEEE International Pulsed Power Conference, 1999) Samaranayake W J M; Miyahara Y; Namihira T; Katsuki SItem Characteristics of Ozone Production by Pulsed Power(12th IEEE International Pulsed Power Conference, 1999) Samaranayake, W.J.M.; Miyahara, Y.; Katsuki, S.; Lisitsyn I; Hackam, R.; Akiyama, H.Item Electrolyte Electroreflectance Study of CdIn2Se4 Liquid Junction Solar cells(American Physical Soc. Meeting, Los Angeles,USA, 1983) Tomkiewicz M; Siripala WItem The Interrelation Between the Potential Distribution and the Dark Charge Transfer Across n-TiO2 - Aqueous Electrolyte Interface(Symposia on Photoelectrochemical Process and Measurements Techniques for Photoelectrochemical Solar Cells, 1981) Tomkiewicz M; Siripala WItem A Study of CuInS2 Thin Films for Photovoltaic Applications(Proceedings of the Technical Session of Institute of Physics, 1999) Wijesundera, R.P.; Nadesalingam, M.P.; Siripala, W.; Jayasuriya, K.D.; Kalingamudali, S.R.D.; Jayanetti, J.K.D.S.; de Silva, K.T.L.Thin films of copper indium disulphide (CuInS2) on Ti Substrate were prepared by annealing potentiastatically electrodeposited Cu-In alloy in H2S gas at 5500 C. Films were characteristised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectral response in a polysulphide electrolyte. XRD measurements revealed the formation of the polysrystaline CuInS2 thin films and the abscence of any other phases. SEM showed the formation of crystallites having the size about 0.2 ?m. Variations of spectral response, open-circuit voltage (Voc) and short circuit current (Isc) with annealing in air have been studied. As deposited CuInS2 films exhibit a direct band gap of 1.5 eV, and shows n-type behaviour when used in a Photoelectrochemical (PEC) cell. Heat treatment shows a considerable enhancement of the photoresponse.Item Growth and Characterization of Copper Indium Diselenide(Proceedings of the Technical Session of Institute of Physics, Sri Lanka, 1996) Chithrani, B.D.; de Silva, K.T.L.; Jayanetti, J.K.D.S.; Siripala, W.CuInSe2 thin films were prepared on Ti plates by electrodeposition from an aqueous solution containing CuCl2, InCl3 and SeO2. The deposition was carried out at -0.5V Vs SCE. X-ray diffraction and Scanning electron microscopy have been used to study the crystallographic and morphological properties of the samples. Effects of annealing in air have also been monitored. Apparent bulk structure changes have been observed during annealing. Annealing of films at 350 0C was found to result in the formation of CuInSe2 films having a chalcopyrite structure, indicating that the samples are of good quality.Item Computational Study of I-V characteristics of ITO/Cu2 O/Metal junctions, Technical Session of Institute of Physics(Processing of the Technical Session of Institute of Physics, 1999) Wijesinghe, W.M.P.L.; Siripala, W.; Jayasuriya, K.D.; Kalingamudali, S.R.D.A theoretical model for current-voltage (I-V) characteristics of back-to-back diode systems was developed using the ideal diode equation. A computer model was developed using the language C++ to fit the experimental data to the theoretical equation and to determine the ideality factors and reverse saturation currents of each diode. This model was tested with commercial back-to-back diode systems. The values obtained for the above parameters from the theoretical fits were in very good agreement with the standard values. The experimental I-V characteristics data obtained for fabricated ITO/Cu2O/Metal (Au, Ag and Hg) structures were fitted to the model and values for the relevent parameters were obtained. These values indicate that the fabricated systems are back to back diodes except the ITO//Cu2O/Hg structure. Using this model, a good understanding of I-V characteristics of metal-semiconductor-metal diodes can be gained and thereby the quality of junction devices can be tested.