Innovalight, a company exploring the ability to print extremely thin solar cell materials on top of conducting substrates, has brought in $18 million in fourth-round venture capital, according to a filing with the SEC. Based in Sunnyvale, Calif., it is backed by EDB Investments, Vertex Venture Holdings, Apax Partners, ARCH Venture Partners, Convexa Capital, Harris & Harris Group, Sevin Rosen Funds and Triton Ventures.