GaN heterostructures with diamond and graphene

The full performance of GaN devices for high power applications is not exploited due to their self-heating. Possible solutions are the integration of materials with high heat conductivity i.e., single crystalline diamond and graphene layers. We report the growth of single crystalline (0001)-oriented GaN thin films on (100), (110) and (111) diamond single crystals studied by transmission electron microscopy (TEM) in cross-sections. As for graphene, we show a high quality GaN layer that was deposited on patterned graphene layers and 6H-SiC. The atomic structures of the interfaces in the heterostructure are studied using aberration-corrected scanning TEM combined with energy dispersive x-ray and electron energy-loss spectroscopy

Nitride Nanowires for Light Emitting Diodes

International audienceThis chapter describes the present status of nitride nanowire (NW) light emitting diodes (LEDs). The main focus is on the NW synthesized by a bottom-up approach. NW growth methods are described and the device processing is presented. Different realizations of NW LEDs are reviewed, grouped by their spectral domain and the targeted applications. Existing challenges of NW technology for LEDs are analyzed. New functionalities offered by the NW geometry are described, namely the use of NWs to create mechanically flexible light sources