Modulation of the photoluminescence of SrTiO3(001) by means of fluorhydric acid etching combined with Ar+ ion bombardment

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.