Dr. Angelo Mascarenhas is an NREL Fellow, and Manager of the Materials Physics group at NREL. He received his PhD in Physics from the University of Pittsburgh in 1986 and did postdoctoral research with at SERI (formerly at RCA David Sarnoff Labs.). Since then he has been working at NREL in the area of spectroscopic research on semiconductor materials for photonics and advanced Solar Cells and has done extensive research on harnessing the material consequences of semiconductor alloy instabilities such as spontaneous ordering and spontaneous composition modulation for optoelectronic applications. Dr. Mascarenhas introduced the study of dilute bismide alloys as an analogous counterpart of dilute nitride alloys, which has significant implications for the field of spintronics, high efficiency solar cells, solid state lighting, and communications lasers. He currently investigates approaches for making amber/green LEDs for solid-state lighting applications, novel architectures for high-efficiency solar cells, and the localized-delocalized transitions in semiconductor alloys. He has supervised 22 postdoctoral scientists and 3 Ph.D. students, is an author of about 300 scientific publications, six book chapters, seven invited papers, editor of a book on Spontaneous Ordering, and has three issued patents (6 pending). He is a fellow of RASEI, a joint NREL-Univ. Colorado Renewable Energy Institute.