Study of phase separation and ordering in indium gallium nitride and aluminium indium gallium nitride: Experimental and computer modeling.

摘要

A comprehensive study examines the phase behaviour of InGaN and AlInGaN including growth characterization and computer modeling. InGaN alloys were grown with up to 50% InGaN and studied for phase separation and ordering. The AlInGaN system has been studied with discovery of the Self Assembled Super-Lattice (SASL) and the Strain Equilibrium Indium (In) Incorporation Effect. Computer modeling was performed using a strain based Valence Force Field (VFF) model combined with a Monte Carlo method to study both the composition pulling and the Strain Equilibrium In Incorporation Effect.;In the InGaN system, both phase separation and ordering behaviour in the InGaN system was studied extensively. Using Transmission Electron Microscopy, the presence of simultaneous phase separation and (0002) ordering was confirmed. The composition pulling effect was also studied in the InGaN system. VFF computer modeling was successfully used to predict the composition of highly strained InGaN films based on the bulk composition.;In the AlInGaN system, the SASL effect was discovered using Transmission Electron Microscopy. In addition the Strain Equilibrium In Incorporation Effect was discovered using a combination of Transmission Electron Microscopy and X-ray diffraction.;Using a VFF Metropolis Monte Carlo algorithm, the Strain Equilibrium In Incorporation Effect has been studied. The computer model has been able to predict the In incorporation behaviour of highly strained films in the AlInGaN system and has confirmed that the strain energy is the primary factor determining the In composition in strained AlInGaN films.