Modelling of nanoscale phenomenon : quantum dot nucleation

Abstract

There has been a tremendous increase in interest on gallium nitride (GaN) since 1989 when it was shown by the Nichia group [1], the possible capabilities obtainable from GaN. However it was only recently that intense research efforts have been dedicated to developing high-quality GaN due to the recent breakthroughs in epitaxy techniques to grow GaN [2,3]. High quality GaN is difficult to grow due to its high susceptibility to form dislocations [4], need of extreme conditions for growth and the lack of latticematched substrates [5,6]. With recent available epitaxy techniques, some attention had been given to growing GaN quantum dots. Quantum dots (QDs) are nano-islands or structures that exhibit zero-dimension density-of-states and are ideal for use in various optical and opto-electronic applications [7]. However, due to their extreme small size, precise instrumentation for in situ monitoring of their growth process is not available. In addition, GaN QDs have in many ways displayed unique growth characteristics, which are different from other group III-V quantum dots systems such InAs/GaAs. Hence, it is proposed here to conduct an atomistic simulation to study the nucleation process of GaN QDs on aluminium nitride (A1N) substrate.