Temperature dependence of photoluminescence from mono-dispersed Si nanoparticles

The temperature dependence of photoluminescence (PL) from mono-dispersed Si nanoparticles was studied from 4 to 300 K. Si nanoparticles produced by pulsed laser ablation in He background gas were sorted into the 6 nm size range by a differential mobility analyzer (DMA). The spread of the size distribution was narrowed to a geometrical standard deviation $\sigma_g = 1.05$. On decreasing the temperature from 300 to 4 K, the intensity of the PL spectra increased gradually, peaked at about 60 K, and then decreased rapidly. The temperature dependences of the intensity and the full width at half maximum (FWHM) on the PL spectra are discussed in terms of radiative and nonradiative decay rates