Visible Electroluminescence from Spherical-Shaped Silicon Nanocrystals

Abstract

We fabricated light emitting diodes (LEDs) using spherically shaped nanocrystalline silicon (nc-Si), which was formed through very high frequency (VHF; 144 MHz) plasma decomposition of SiH4. In addition, we successfully reduced the roughness of the surface and part of the voids separating the dots by finding the adequate annealing conditions. Red electroluminescence was also observed at 12 V with the naked eye at room temperature under forward bias condition. It is suggested that the origin of the electroluminescence (EL) from Si nanocrystals is due to recombination centers in Si nanocrystals by the comparison of EL and photoluminescence spectra.