San Jose-based solar cell developer TetraSun, which is owned by JX Nippon Oil & Energy Corporation and other investors, has been acquired by solar module manufacturer First Solar. Financial terms of the acquisition were not announced by the company. First Solar said that TetraSun's solar cell architecture is capable of conversion efficiencies exceeding 21 percent with commercial-scale manufacturing costs comparable to conventional multicrystalline silicon solar cells. First Solar said it will begin commercial-scale manufacturing using TetraSun's technology in the second half of 2014. As part of the deal, First Solar said it will hire all fourteen of TetraSun's employees, and continue to maintain those operations in San Jose.