Influence of selenous acid microadditive on electrochemical formation of CdS thin films

- Electrochemical systems with various concentrations of H2SeO3 were studied.
- Based on experimental data and thermodynamic calculations the steps in CdS formation in the presence of H2SeO3 were proposed.
- The influence of H2SeO3 present in the electrolyte on the properties of CdS is revealed.
- The optimal concentration of the H2SeO3 microadditive is determined.

Electrodeposition of CdS in the presence of H2SeO3 microadditive at 50 °C in an aqueous solution was studied. Addition of H2SeO3 affects the growth of CdS thin films and improves structure ordering, coverage, and stoichiometry. The effect of H2SeO3 is advantageous as allows simultaneously improve the coverage and decrease the thickness of the CdS film during the electrodeposition process. Elemental Se detected in the as-deposited CdS films can be easily removed by a vacuum thermal treatment. The reported approach allows the electrodeposition of uniform polycrystalline photosensitive CdS thin films at reduced temperature. The optimal concentration of the microadditive at given conditions is reported.