Green and red electroluminescence from CdS powder electrodes in aqueous solutions

Abstract

The room temperature electroluminescence properties of CdS powder (polycrystalline) electrodes have been investigated in aqueous solutions under various experimental conditions. Red emission is observed from all the CdS electrodes annealed at 400-600 °C, whereas green emission, which has previously been observed only from single crystal CdS electrodes, is also observed from the powder electrodes annealed at 600 °C. Both the red and the green emission intensities increase with an increase in the applied (negative) potential up to a critical value (-1.6 V vs Ag/AgCl); above this value there is a decrease in the intensity. The increase in the green emission is much stronger than the increase in..