Solar cells based on cadmium and tellurium could move closer to theoretical levels of efficiency as a result of research at the Department of Energy’s Oak Ridge National Laboratory.   A team led by Jonathan Poplawsky of the Center for Nanophase Materials Sciences used advanced microscopy techniques to discover efficiency differences of crystalline structures of various mixtures of cadmium, tellurium and selenium. In fact, selenium is an integral part of the formulation that resulted in a wor...