Martin Roscheisen is an American-Austrian tech entrepreneur. He is CEO and  co-founder of US-based unicorn Diamond Foundry, the first certified carbon-neutral producer of lab-grown diamonds. He has worked there since 2012, prior to the company’s official establishment in 2013.Roscheisen holds a PhD in computer science from Stanford University, where his classmates included Google founders Larry Page and Sergey Brin. He is one of the first generation of internet entrepreneurs, and has been involved in starting a number of companies. Before starting Diamond Foundry, Roscheisen headed the $640m solar startup Nanosolar from 2002–2010 as its CEO and founder. This was Silicon Valley's first solar power tech startup financed by American venture capital and, at the time, the highest-valued solar startup.When Nanosolar closed due to cheaper competition from China, much of its remaining technical expertise and resources went to setting up Diamond Foundry.In addition, Roscheisen was also formerlyCEO and the founder of eGroups. One of the first social media platforms to reach 50m users, the firm was acquired by Yahoo!.CTO and co-founder of enterprise software firm TradingDynamics, which sold to Ariba for $1.2bn.CTO and co-founder of FindLaw, a leading Internet legal site eventually sold to Thomson Reuters.In 2003, Fortune Magazine named Roscheisen one of America’s 40 Under 40, and one of the top 10 entrepreneurs in the country.