The influence of thermal and laser annealing on tin-induced crystallization of amorphous silicon in layered a-Si\Sn\a-Si films

The formation of silicon nanocrystals during tin-induced crystallization in layered a -Si\Sn\ a -Si films at temperatures of 600–800 °C and under the influence of laser light is investigated using Raman and photoluminescence spectroscopy, optical, electron, and atomic force microscopy . The effect of heat treatment temperature on nanocrystal size, concentration, and the efficiency of laser-stimulated metal-induced crystallization (MIC) upon further exposure to a high-power laser is determined. Conditions are identified under which about 90 % of amorphous silicon transition to silicon nanocrystals with sizes of ∼2.7 nm, exhibiting quantum dot properties. The effect of the Sn layer thickness on the size and concentration of Si nanocrystals formed during MIC is also studied. It is shown that the photoluminescence spectrum intensity of heat-treated a -Si\Sn\ a -Si films correlates with the concentration of Si nanocrystals, and its overall appearance corresponds to the photoluminescence spectrum of nc -Si in a SiO 2 matrix.