Although yet to be independently verified, Sunovia Energy Technologies and partner EPIR Technologies have claimed a dramatic increase in the performance of cadmium telluride (CdTe) based solar cells. According to the company it has shattered the previous world record for open circuit voltage (Voc) readings by 45%. Sunovia said that an open circuit voltages of 1.34 V and 1.75 V were achieved with a single-junction and two-junction configurations, respectively.
The 1.34 V value for the single-junction cell was more than 95% of the theoretical upper limit for the II-VI alloy used. Sunovia said that the highest reported Voc for a CdTe solar cell was 0.91 V, representing about 76% of the theoretical maximum for CdTe. The partners claimed that its two-junction II-VI cell would reach production efficiencies over 35%.
“These are by far the highest Voc measurements ever exhibited by a CdTe-based solar cell. There is no data in the literature that comes close to what we have achieved, and we believe that our two-junction device also represents the first ever high efficiency monolithic, two-junction solar cell using CdTe or any other II-VI material,” noted Dr. Michael Carmody, Senior Director for Development of Photovoltaic Materials at EPIR Technologies. “The company’s two-junction II-VI on Silicon design will reach production efficiencies over 35% and will cost only a small fraction of the cost of three-junction III-V solar cells. Three-junction II-VI on Silicon cells will have even higher production efficiencies without much added cost.”
The partners are expanding their pilot production facilities, and are working to complete the initial 100MW of manufacturing capacity.