Sunovia researchers shatter world record open circuit Voltage (Voc) for cadmium telluride (CdTe) thin film solar cells by over 45%, dramatically raising the theoretical potential efficiency of CdTe thin film solar cells.
Sunovia Energy Technologies, Inc. and partner EPIR Technologies, Inc. have announced that they have fabricated single-junction and two-junction cadmium telluride (CdTe) based solar cells that have far surpassed the long-standing world record open circuit voltage (Voc) for thin film CdTe solar cells.
The Partners' single-junction and two-junction devices exceeded the highest Voc values ever reported publicly by research institutions on thin film CdTe solar cells (including NREL and others) by over 45%.
They called the Voc breakthroughs significant because the amount of electric power generated by a solar cell is directly proportional to its open circuit voltage. So doubling the Voc of a solar cell results in a doubling of power output, if all other characteristics remain the same.
So the results reported by the partners will enable the companies to create solar cells with much higher efficiencies than other CdTe-based solar cell technologies.
Open circuit voltage has traditionally been the most difficult performance metric to optimize in CdTe solar cells and the Partners' CdTe-based (also known as II-VI materials) solar cells achieved open circuit voltages of 1.34 V and 1.75 V in the single-junction and two-junction configurations, respectively. The 1.34 V value in the single-junction configuration is more than 95% of the theoretical upper limit for the II-VI alloy used by the Partners.
In contrast, the highest reported Voc for a CdTe solar cell is 0.91 V, representing about 76% of the theoretical maximum for CdTe. By fabricating II-VI solar cells with open circuit voltages close to the theoretical upper limit for the materials utilized, the Partners have developed next-generation, high efficiency CdTe-based solar cells, which will accelerate the push of clean solar-generated electricity towards grid parity.
The Partners recently announced the expansion of their pilot production facilities, and are working to complete the initial 100 MW of manufacturing capacity.
Their proprietary cell manufacturing process requires substantially less space than competing solar technologies, and is scalable at a fraction of the previous cost. The utilization of a silicon (Si) substrate greatly lowers manufacturing costs and allows the Partners to employ proven manufacturing techniques and equipment developed over more than 40 years during the evolution of the micro-chip industry.
According to Dr. Michael Carmody, Senior Director for Development of Photovoltaic Materials at EPIR Technologies, "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. 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."
Dr. Siva Sivananthan, founder and CEO of EPIR Technologies says, "This ground breaking achievement could not have occurred without Senator Dick Durbin's support and commitment. Over the past 2 years, EPIR and Sunovia have collectively grown from 25 to almost 70 employees and will add many more manufacturing jobs as we commercialize this technology. These breakthroughs are a tremendous step forward for our national security and energy independence goals. I am tremendously proud of the team at EPIR, and am pleased to be partnered with such an outstanding group of professionals at Sunovia."
Carl Smith, founder and CEO of Sunovia Energy Technologies, Inc., added, "In one of the most difficult economic climates in history, we have remained intently focused on our goals, and together we have grown rapidly. This new solar technology that Dr. Sivananthan's team has invented is unprecedented, and has far-reaching benefits that will not only positively impact national security, energy independence and our environment, but will also bring manufacturing jobs back to the United States."
About Sunovia Energy Technologies, Inc
Sunovia Energy Technologies is a Sarasota, FL-based company that commercializes and markets products within the LED lighting and solar markets that reduce carbon emissions promote national security and preserve the environment. Sunovia owns the exclusive marketing rights to products produced by EPIR Technologies, Inc., including infrared sensors and devices for the civilian and military night vision markets.
Sunovia's LED lighting technologies are among the most cost and energy-efficient in the world, and are marketed under the brand name EvoLucia(TM) (www.evolucialighting.com ).
Sunovia owns a significant equity interest in Illinois-based EPIR Technologies, Inc., the pioneer of single crystal II-VI solar modules and a global leader in the field of IR sensors and IR imaging. EPIR's collective infrared knowledge and experience is believed to exceed that of any company in the world. Its founder, Chairman and CEO Dr. Sivalingam Sivananthan, is a recognized world leader in HgCdTe growth.
EPIR holds the patent for growing CdTe directly on a Si readout integrated circuit, for which the company developed a manufacturing capability with Congressional support. Sunovia and EPIR co-own the solar technologies and solar products that are developed under the Exclusive Partnership Agreement.
The Partners have a network of close collaborative relationships, including the Army Research Laboratory, the National Renewable Energy Laboratory, the Night Vision Electronic Sensors Directorate, BAE Systems, and other laboratories around the world.