Electroluminescence emission of crystalline silicon nanoclusters grown at a low temperature

With CO₂ laser assistance, crystalline silicon nanoclusters were formed in silicon nitride films deposited at a low temperature and without post-annealing using a conventional plasma-enhanced chemical vapour deposition system. The crystalline silicon nanoclusters embedded in silicon nitride matrices were observed from high-resolution transmission electron microscopy (HRTEM) images. According to experimental results of photoluminescence (PL) spectra and HRTEM images, the energy gap E(eV) as a function of diameter d (nm) of crystalline silicon nanoclusters can be expressed as E(eV) = 1.17+(11.6/d²). The intensity and emission energy of the PL spectra of the laser-assisted silicon nitride films increased with the NH₃ flow rate. Electroluminescence emission of light-emitting devices using the crystalline silicon nanoclusters was demonstrated.