Effects of laser irradiation on the self-assembly of MnAs nanoparticles in a GaAs matrix

We investigate the effects of laser irradiation on the self-assembly of MnAs nanoparticles during solid-phase decomposition in a GaAs matrix. It is found that laser irradiation suppresses the growth of MnAs nanoparticles from small to large size, and that the median diameter D ₁ in the size distribution of small MnAs nanoparticles depends on the incident photon energy E following D ₁ ∼ E ^-1/5. We explain this behavior by the desorption of Mn atoms on the MnAs nanoparticle surface due to resonant optical absorption, in which incident photons excite intersubband electronic transitions between the quantized energy levels in the MnAs nanoparticles.