Metal-semiconductor nanoheterostructures with an AlGaN quantum well and in-situ formed surface Al nanoislands

We report on fabrication and studies of composite heterostuctures consisting of an Al$_{0.55}$Ga$_{0.45}$N/Al$_{0.8}$Ga$_{0.2}$N quantum well and surface Al nanoislands, grown by plasma-assisted molecularbeam epitaxy on $c$-sapphire substrates. The influence of a substrate temperature varied between 320 and 700$^\circ$C on the size and density of the deposited Al nanoislands is evaluated. The effect of Al nanoislands on decay kinetics of the quantum well middle-ultraviolet photoluminescence has been investigated by time resolved photoluminescence. The samples with the maximum density of Al nanoislands of 10$^8$ cm$^{-2}$ and lateral dimensions in the range of 100–500 nm demonstrated shortening of the photoluminescence lifetime, induced by interaction of the emitting quantum well and the plasmonic metal particles.