We report a method to modulate the photoluminescence (PL) of SrTiO3(001) at room temperature by fluorhydric (HF) acid etching and Ar+ ion bombardment. The PL of the virgin sample is in the blue/green range, which can be enhanced in intensity by a factor of 7.2 after being fully etched in HF acid with the peak shape being unchanged. Ar+ ion bombardment of SrTiO3 can blueshift the overall PL, and the peak maximum becomes centred at 403 nm. After fully etching the ion-bombarded sample in HF, the PL peak stays in the blue light range, but its intensity increases to 17.5 times that of the virgin one. Oxygen vacancies assumed to be produced on the lateral sides of SrTiO3 nanograins are responsible for the PL emissions, and their variations in number and nature are attributed to the PL modulation.

An approach combining back- and front-side doping of Ce3+ in Si nanocrystals embedded in SiO2 (nc-Si:SiO2) with hydrogen passivation has been developed, which largely enhances the photoluminescence (PL) of Si nanocrystals. The sample of nc-Si:SiO2 was prepared via a phase separation process of SiO thin film at 1100 °C. For the back-side doping, a SiO2 buffer layer was placed between the CeF3 layer and SiO one, thus Ce3+ doping could be accomplished without disrupting the phase separation of SiO. The front-side doping was then followed by evaporating CeF3 onto the front surface of the formed nc-Si:SiO2, followed by diffusion annealing at 500 °C. The double-side doping enhanced the PL intensity of Si nanocrystals by a factor of 7.3. After hydrogenation of the double-side doped sample, a 14.6-fold increase in the PL intensity was finally achieved.