Chemistry
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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 Is it possible to grow stable p-type CdS layers suitable for fabrication of electronic devices?(University of Malaya, Malaysia, 2013) Kiriarachchi, H.D.; Lamahewage, L.H.S.N.S.; Wickramasinghe, W.A.S.; de Silva, D.S.M.; Pathiratne, K.A.S.; Dharmadasa, I.M.CdS is a technologically important wide bandgap window material with some unique properties showing highest conversion efficiencies in thin film solar cells based on CdTe and CuInGaSe2 absorber materials. n-CdS/CdTe and n-CdS/CuInGaSe2 hetero-interfaces based solar cells have demonstrated 18.7% and 20.3% lab-scale solar cell efficiencies to date. Both these devices are fabricated based on n-type CdS window material. Recent work on graded bandgap devices using p-type AlGaAs window materials experimentally demonstrated highest Voc values of 1175 mV together with highest possible FF values ~0.85, and therefore if p-CdS can be grown, it provides another route to improve solar cell efficiencies and open doors for many other electronic devices. There are several attempts to grow Cu-doped p-CdS in the literature but the follow-up research work or devices based on p-CdS are scarce. In this research programme of solar energy materials development, using electrochemical growth method, p-type CdS was observed for certain layers. However, the stability of p-type CdS is found to be weak and these results are presented and discussed in this paper.Item Selenium content in daily meals consumed by Sri Lankans-A preliminary study(Institute of Chemistry Ceylon, 2015) Kiridena, K.M.S.D.; de Silva, D.S.M.; Wimalasena, S.; Kannangara, A.T.; Weerarathna, H.P.Item Effect of stirring rate of the electrolyte on properties of electrodeposted CdS layers(International photovoltaic solar energy conference-Solar Asia, Pune, India, 2015) Atapattu, H.Y.R.; de Silva, D.S.M.; Pathiratne, K.A.S.; Dharmadasa, I.M.Item A comparison of performance between chemical bath deposited and electrochemical bath deposited CdS thin films in CdS/CdTe thin film solar cells(The U.S. Workshop on the Physics and Chemistry of II-VI materials, 2013) Pathiratne, K.A.S.; de Silva, D.S.M.; Kumarasinghe, K.D.M.S.P.K.; Dasanayake, B.S.; Colegrove, E.; Xin Zheng, R.D.; Sivananthan, S.Item A study on solution grown CdZnS as a window layer for solar applications(The U.S. Workshop on the Physics and Chemistry of II-VI materials, 2013) Dassanayake, B.S.; de Silva, D.S.M.; Pathiratne, K.A.S.; Colegrove, E.; Zheng, X.; Dhere, R.; Sivananthan, S.Item Fabrication of CdS (n-type) and CdTe (p-type) Thin Film Semiconductor Materials via Electrodeposition(Institute of Chemistry Ceylon, 2013) Sandaruwan, K.A.I.; Athukorala, P.S.; Pathiratne, K.A.S.; de Silva, D.S.M.; Dharmadasa, I.M.Item Selenium content in rice consumed by Sri Lankans(Institute of Chemistry Ceylon, 2013) Mahagama, S.; de Silva, D.S.M.; Wimalasena, S.Item Fabrication of CdS (p-type) thin film semiconductors via electrodepostion(Institute of Chemistry Ceylon, 2013) Kiriarachchi, H.D.; Lamahewage, H.S.N.S.; Pathiratne, K.A.S.; de Silva, D.S.M.; Dharmadasa, I.M.Item Green building materials from spinifex(Commonwealth Forestry Association, 2010) Gamage, H.; de Silva, D.S.M.; Flutter, N.; O'Rourke, T.; Memmott, P.; Martin, D.; Schmidt, S.