Photoluminescence from amorphous SiO2/Silicon/amorphous SiO2single quantum well structures

Abstract

AbstractAmorphous silicon dioxide/silicon/amorphous silicon dioxide single quantum well structures were fabricated by oxygen implantation followed by thermal oxidation. No photoluminescence (PL) was observed from the as grown samples. We found that annealing in hydrogen allows the single quantum well (SQW) structures to emit two-peak (blue and yellow) PL at room temperature (RT). The blue PL (2.9 eV) does not change with the thickness of Si layers or the temperature. The yellow peak varied from 2.0 eV to 2.4 eV with thinning of the Si layer from 5 nm to 0.5 nm. Lowering the temperature also changed the yellow peak position of the 1.5 nm Si-SQW structure from 2.3 eV (RT) to 2.6 eV (8.4 K). We conclude that the blue PL is from SiO2 and the yellow PL is caused by a recombination process in the Si-SQW.