Electrocrystallization of CdSe upon various substrates. Structural arrangement and photoelectrochemical performance

The growth of cadmium chalcogenide thin film semiconductors, in the context of a typical electrolytic method of formation with an aqueous bath, is to a large extent determined by the deposition substrate, together with the po tential, for a given electrolyte composition and temperature. The effect of various substrates ([100]-oriented Ni, commercially pure Ni, Ti) and proce dures (Ni electropolishing, Ti anodization, double-step deposition, etc.) o n the structural arrangement and the resulting photoelectrochemical (PE) be havior of cathodically electroplated CdSe layers is presented. The outcome of the preparation process is analyzed in terms of structural-optical prope rties relation. As verified, some microcrystalline, porous samples give hig her PE efficiencies than larger-grained ones, owing to the increased contac t area with the PE redox electrolyte and possibly the establishment of a pa rticular charge transfer mechanism in the solid. The latter is associated w ith the existence of a nanostructure. (C) 2000 Elsevier Science B.V. All ri ghts reserved.