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The effect of deliberately added CI-, Cu2+ and Ag + on the performance of electrodeposited thin-film CdS/CdTe photovoltaic devices has been studied. It has been found that the incorporation of CI-from the deposition electrolytes into both CdS and CdTe films is essential for the production of high-efficiency devices. The incorporation of Cu2+ into CdTe was found to result in a loss in performance for concentrations in the electrolyte >30 ppb, corresponding to a concentration of ca. lo2' ~r n -~ Cu in the film. Below 30 ppb, there is some evidence that Cu2+ may enhance the performance of the device. The incorporation of Ag into CdTe was found to be deleterious at concentrations in the electrolyte as low as the detection limit (5 ppb). By controlling these species within the determined limits, it was possible to produce high-efficiency devices over a period of 4-5 months (> 100 depositions) from a single electrolyte.

Arrays of dielectric resonators-illuminated by an antenna-are used to ignite and sustain multiple microwave plasmas in parallel. Calcium titanate cylindrical resonators were arranged in a linear array with separation distances between 0.5 and 5 mm. The operating frequency was near the HEM 111 resonance of 1.1 GHz. Paschen curves of the breakdown field and voltage in argon atmosphere are consistent with parallel plate microwave breakdown except within discharge gaps of 1 mm or less. Sustaining of argon plasma between 0.5 Torr and 1 atm within the array is found to alter the electromagnetic scattering from the dielectric resonators, suggesting applications in plasma-reconfigurable metamaterials and photonic crystals.

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The cathodic electrodeposition of cadmium telluride from aqueous solutions has been studied by cyclic voltammetry and potential step techniques at stationary and rotating electrodes. A new theoretical model of the deposition process has been proposed for the case where the substrate is completely covered with normalCdTe . It is based on the assumption that Cd atoms are only incorporated at Te sites and Te atoms at Cd sites. As a consequence, deposition rates are determined by surface coverage terms as well as by charge and mass transfer. Unusual nonsteady state effects have been observed during perturbation of the electrode potential or mass‐transfer rate. These effects have been explained successfully by the theory in terms of the relaxation of surface adatom coverages.