Howard Branz, Ph.D., a nationally and internationally renowned scientist with achievements in physics, materials science, and device engineering related to renewable energy. Branz has led NREL's amorphous silicon photovoltaic development for more than 5 years and all of NREL's silicon research. Primary research interests include film crystal silicon photovoltaics; defects, metastability, and diffusion in semiconductors; amorphous semiconductors; mechanisms of film and epitaxial silicon growth; and nanostructured black silicon.