Structural characterization of GaN grown by hydrogen-assisted ECR-MBE using electron microscopy

Self-assembled GaN nano-rods grown directly on (111) Si substrates: Dependence on growth conditions

“…Yet, the current nitride materials are still far from ideal quality and have a very high dislocation density around 10 8 -10 10 cm À2 due to the lack of homogeneous substrate, which is the major obstacle to widely open the GaN-related market era. Recently, it has been reported that dislocation-and strain-free GaN materials can be obtained by forming nanoscale structures, such as columnar structures [1][2][3] and pyramidal hillocks [4] utilizing various methods, such as catalytic growth, patterning technique, and self-assembling process. Among them, the recent development of self-assembled nanorods formed on silicon and sapphire substrates at an unprecedented pace looks promising due to its extremely high quality and the relatively easy size controllability.…”

Stimulated emission from GaN nanocolumns

“…These nanocolumns were independently grown with their c-axis perpendicular to the substrate surface. Until now, many studies on nitride nanoscale columnar structures have been reported, for example, growth of nanocolumns by ECR-MBE [4] and HVPE [5], fabrication of nanocolumns by reactive ion etching [6] and photon-assisted anodic etching [7], growth on (111) Si substrate [8], evaluation of optical properties [9,10], growth of GaN/AlGaN [11,12] and InGaN/GaN [1] quantum wells in the nanocolumns, and so on. In this paper, we describe the optical properties of GaN nanocolumns using room temperature photoluminescence, under low and high (photopump) excitation conditions.…”

Gallium Nitride: An Overview of Structural Defects

“…Inversion domains were also believed to be linked to the formation of columnar structure with a faceted surface and stacking faults. T. Araki (Araki et al, 2000) studied GaN grown on sapphire by hydrogen-assisted electron cyclotron resonance-molecular beam epitaxy, www.intechopen.com and found that GaN layer change from 2-dimension to 3-dimension growth by adding hydrogen to nitrogen plasma. They assumed that the inversion domains of polarity existed on the buffer layer, which led to the formation of this defect.…”