Analysis of the Chemical Bath and its Effect on the Physical Properties of CdS/ITO thin Films

Cadmium sulphide (CdS) thin films deposited on indium tin oxide (ITO) substrates were prepared by thechemical bath deposition technique at different values of pH and pNH3. This was made in order to analyze theinfluence of the initial chemical composition of the bath on some physical properties of th...

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Detalhes bibliográficos
Autores: S. Herrera, C. M. Ramos, R. Patiño, J. L. Peña, W. Cauich, A. I. Oliva
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2006
País:México
Recursos:Centro de Investigación y de Estudios Avanzados del IPN
Repositorio:Redalyc-CINVESTAV
OAI Identifier:oai:redalyc.org:46436568
Acesso em linha:https://www.redalyc.org/articulo.oa?id=46436568
Access Level:acceso abierto
Palavra-chave:Física, Astronomía y Matemáticas
Cadmium sulphide
Semiconductor film
Predominance diagrams
Chemical bath analysis
Descrição
Resumo:Cadmium sulphide (CdS) thin films deposited on indium tin oxide (ITO) substrates were prepared by thechemical bath deposition technique at different values of pH and pNH3. This was made in order to analyze theinfluence of the initial chemical composition of the bath on some physical properties of the final CdS films, usedas optical windows for solar cells. The mechanism proposed in the literature for this deposition involves thetetra-ammonium cadmium (II) complex, Cd(NH3)2+4 , at the start of the reaction. Following this mechanism,the change in the concentration of Cd(NH3)2+4 gives a variation in the rate of deposition with the correspondingmodification in the quality of the film. Therefore, the predominance zone diagram of Cd2+ species in solution asa function of the values of pH and pNH3was used to analyze the reasons why the CdS/ITO thin films are favoredin just a narrow range of ammonium and hydroxide concentrations. To obtain useful films, the results showedthat low ammonium concentrations must be avoided at high pH values as well as high ammonium concentrationsat lower pH values.