Two US startups are breaking solar efficiency records in their quest to bring clean, cost-effective, eco-friendly energy to a power grid near you. Alta Devices, based in Santa Clara, CA, has achieved a 23.5 percent efficiency rating with its standard solar panel, while Semprius, a Durham, NC company, has achieved a rating of 33.9 percent with its concentrated photovoltaic offering -- besting the previous records of 22.9 percent and 33 percent, respectively. Interestingly enough, both outfits chose to utilize a new material to construct their sun-sopping cells: gallium arsenide . The material, while more expensive, is better suited for absorbing the sun's energy, especially when compared to silicon , the cheaper element typically used. Alta and Semprius are looking to proliferate solar power by further refining the technology, making its price per kilowatt equivalent to that of fossil fuels without the use of government subsides. Here comes the sun...