Substantial Improvements In Growth Of Single-Crystal Cadmium Telluride On Silicon

Sunovia Energy Technologies and EPIR Technologies have announced substantial improvements in their process of growing very-high-quality single-crystal cadmium telluride on silicon. This achievement is the foundational precursor for creating ultra-high-efficiency multi-junction solar cells with substantially lower costs than current multi-junction photovoltaic (PV) approaches.

These process improvements involved increasing single-crystal growth rates by over 500 percent, allowing for lower processing times per wafer and more PV cells per deposition chamber per day, increasing throughput and lowering costs. We believe this breakthrough achievement will accelerate the Companies demonstration of an initial 20MW manufacturing system for ultra high efficiency, low cost solar cells.

We believe that the advanced manufacturing system can be duplicated for much less than the typical cost for advanced solar cell manufacturing systems in existence today.

Further, deposition uniformity was greatly improved with crystal quality distributions being reduced closer to the 55 arcsecond X-Ray rocking curve width previously reported. Improving uniformity is a noteworthy advancement as it makes larger wafers and larger deposition chambers possible, which aids in increasing throughput and lowering costs.

Sunovia and EPIR's CdTe-on-Si technology is currently being funded and developed to produce high-sensitivity, long-wavelength infrared (IR) imaging technology with much larger formats and substantially lower costs than currently employed technologies. These breakthroughs made in the development of IR technology are directly transferable to the production of high-efficiency, low-cost multi-junction PV cells.

The Companies' approach of growing high-quality II-VI semiconductor materials on low-cost large silicon wafers via EPIR's high throughput deposition (HTD) technology for concentrator photovoltaic (CPV) systems offers several advantages over current technologies, including:

+ The II-VI semiconductor material system offers many different material systems and opportunities to create multi-junction cells which can effectively span the solar spectrum.

+ The use of active silicon growth substrates leverages the silicon electronics industry technology to obtain large and extremely low cost, high quality silicon wafers.

+ II-VI multi-junction solar cells in CPV systems use less than 1/1000th of the Cd and Te of their polycrystalline thin-film counterparts, avoiding concerns of environmental toxicity and raw material supply.

+ The HTD process does not use the highly toxic and flammable materials that III-V semiconductor deposition processes use, and hence does not require extensive and expensive safety systems, allowing faster capacity commissioning and regulatory approval.

+ The HTD process requires less than 20 sq ft per MW of production capability at an investment far less than the $1.5M/MW of current high-efficiency thin-film deposition systems.