Fabrication of semi-polar nano- and micro-scale GaN structures on the vertex of hexagonal GaN pyramids by MOVPE

Controlled growth of hexagonal GaN pyramids by hot-wall MOCVD

The growth evolution of hexagonal GaN pyramids are investigated under various growth conditions. The hexagonal GaN pyramids were grown by hot-wall metal organic chemical vapor deposition – process (hot-wall MOCVD) on a (0001) oriented GaN template. We concluded the growth of the hexagonal GaN pyramids can be divided into two different regimes defined by the adsorption kinetics of the {1101} sur...

Controlled growth of hexagonal GaN pyramids and InGaN QDs

GaN growth on porous silicon by MOVPE

GaN films have been grown at 1050 8C on porous silicon (PS) substrates by metalorganic vapour phase epitaxy. The annealing phase of PS has been studied in temperature range from 300 to 1000 8C during 10 min under a mixture of ammonia (NH3) and hydrogen (H2). The PS samples were characterized after annealing by scanning electronic microscope (SEM). We observed that the annealing under the GaN gr...

the role of task-based techniques on the acquisition of english language structures by the intermediate efl students

this study examines the effetivenss of task-based activities in helping students learn english language structures for a better communication. initially, a michigan test was administered to the two groups of 52 students majoring in english at the allameh ghotb -e- ravandi university to ensure their homogeneity. the students scores on the grammar part of this test were also regarded as their pre...

GaN Nanowires on N-Polar GaN

In this work, the position-controlled growth of GaN nanowires on sapphire wafers and on N-polar GaN templates is presented using selective area vapor-liquid-solid growth in a metalorganic vapor phase reactor. Misoriented sapphire wafers and TMIn acting as surfactant are applied in order to achieve N-polar GaN buffer layers with high crystal and surface quality, suitable for a subsequent nano-pa...