Stress evolution measured during N-polar GaN growth

1. Stress Evolution of N-polar GaN Films on SiCJoan Redwing, Pennsylvania State Univ University Park, DMR 1006763 Heteroepitaxial growth of GaN can occur along either the [0001] (Ga-polar) or the [0001] (N-polar) direction. There is growing interest in N-polar growth as a route to fabricate novel structures, however, the fabrication of N-polar GaN films with low surface roughness by metalorganic chemical vapor deposition remains a challenge. We have utilized in-situ wafer curvature measurements in combination with post-growth structural characterization to study the effects of growth temperature on the stress and surface morphology of N-polar GaN grown on miscutSiC substrates. Our studies reveal that the use of an initial GaN layer grown at reduced temperature leads to a simultaneous reduction in film stress and surface roughness. Stress evolution measured during N-polar GaN growth

2. Outreach Activities on Energy MaterialsJoan Redwing, Pennsylvania State Univ University Park, DMR 1006763 During the first year of the program, we worked with members of the Franklin Institute Museum in Philadelphia, PA and the Penn State MRSEC Center for Nanoscale Science on the development of light emitting diode (LED)-related activities for a cart-based, interactive demonstration kit on energy materials. Over the past year, the PI and her graduate students presented activities from the demonstration kit to K-12 students participating in outreach activities at Penn State such as a Science Leadership Camp for high school students. Prof. Redwing (back of table) assisting Science Leadership campers with bandgap energy demonstration kit..