Light-emitting properties of Si-ion-irradiated SiO2/Si/SiO2 layers

Photoluminescence (PL) from a Si-ion-irradiated SiO2/Si/SiO2 layer on a Si substrate at room temperature has been studied to elucidate the luminescenc e behavior under various post-annealing treatments. A luminescence band aro und 450 nm is observed from the as-irradiated sample, This luminescence ban d is found to originate from the diamagnetic defect, known as the B-2 band, generated by Si ion irradiation. The intensity of tills band increases wit h the increasing annealing temperature up to a critical temperature after S i irradiation. The B-2 Land activates at a lower temperature than the radia tive defect related to the PL peak around 600 nm. After tilts ion-irradiate d samples are annealed at 1100 degrees C, the PL peaks around 450 nm and 60 0 nm originating from radiative defects disappear, and a new PL peak appear s around 720 nm. This luminescence band is associated with the similar to 5 -nm-sized Si nanocrystals produced along the Si layer between SiO2 layers. as determined by high resolution transmission electron microscopy. The inte nsity of the pi, peak fr om the ion-irradiated SiO2/Si/SiO2 laver is strong er than that from the Si-implanted SiO2 film and that from the SiO2/Si/SiO2 layer annealed without Si irradiation.