Effect of illumination on tellurium electrodeposition process in tartrate electrolytes

The effect of illumination on the process of tellurium electrodeposition from electrolytes of the composition: 0.1 - 0.5 M TeO2 + 2 M C4H6O6 + 5 M H2SO4 at 25 deg C has been investigated. Platinum plate, which was preliminarily covered by tellurium from the studied solutions in electrolytic way is used as a cathode. The 500 W bulb is used to illuminate the electrode. It is shown that photosensitivity of Te-electrode depends on the coating thickness and on polarizing current. After switching on of illumination a more positive dark potential is set than before illumination. In the process of pulsed switching on/obb regime the effect of photoactivation is observed, which can be explained by a considerable increase in the electrode surface at the expense of tellurium black formation. It is pointed out that during tellurium electrodeposition from tartrate electrolytes the illumination changes considerably the properties of Te-electrode surface. The illumination also affects specific electric resistance, texture, gleaming of the coatings texture, gleaming of the coatings