A combined approach to fabricating Si nanocrystals with high photoluminescence intensity

This work demonstrates that by combining three methods with different mechanisms to enhance the photoluminescence (PL) intensity of Si nanocrystals embedded in SiO2 (or Si-nc:SiO2), a promising material for developing Si light sources, a very high PL intensity can be achieved. A 30-layered sample of Si-nc:SiO2/SiO2 was prepared by alternatively evaporating SiO and SiO2 onto a Si(1 0 0) substrate followed by thermal annealing at 1100 °C. This multilayered sample possessed a fairly high PL efficiency of 14% as measured by Greenhamʹs method, which was 44 times that of a single-layered one for the same amount of excess Si content. Based on this multilayered sample, treatments of CeF3 doping and hydrogen passivation were subsequently applied, and a high PL intensity which was 167 times that of a single-layered one for the same amount of excess Si content was achieved.