An energetic study on the formation of self-assembled indium arsenide nanostructures grown on indium gallium arsenide/indium phosphide and gallium arsenide substrates

The quantitative relationships between the growth temperature and the sizes of indium arsenide (InAs) nanostructures on both indium gallium arsenide/indium phosphide (InGaAs/InP) and gallium arsenide (GaAs) matrix layers have been determined based upon the experimental results. The atomic diffusion barriers of InAs-on-InGaAs/InP and InAs-on-GaAs are estimated as 0.48 eV and 0.62 eV, respectively. The results, with roughly 20 per cent error bars, match reasonably well with the theoretically simulated data. From a thermal equilibrium picture, a simple but practical model has been developed to calculate the strain-induced elastic energy relaxation during islanding through the estimation of the overall free energy required for interface heteronucleation and new surface formation. The calculated data of elastic energy in the low monolayer (ML) coverage cases are very close to the simulated results published previously. It is expected that such a simple thermodynamic approach can be applied in estimating the energetic budget when developing the growth and surface morphology control strategies.