In 2011, John Simon joined NREL to study novel crystalline substrates for growth of III-V nitride semiconductors for solid-state lighting applications. Since then he has been involved in various projects involving the growth of III-V semiconductor films and devices for solar applications. John helped develop the dynamic hydride vapor phase epitaxy (D-HVPE) system at NREL to grow low-cost III-V devices. Specific research interests include development of low-cost III-V solar cells, high-efficiency multijunction solar cells, III-V semiconductor epitaxy, and development of novel semiconductor devices.

John received his doctorate in electrical engineering from the University of Notre Dame, in Indiana, in 2009 where he studied novel approaches to utilize the polarization fields in III-V nitride semiconductors for improved electronic device performance. He then had a postdoctoral appointment at Yale University where he studied metamorphic buffers for high-efficiency III-V solar cells.