Photoluminescence of Er-implanted KTP and RTP crystals

Abstract

Single crystalline samples of potassium titanyl phosphate (KTP) and rubidium titanyl phosphate (RTP) were implanted with 150 keV Er+ ions to a fluence of 5 × 1015 cm−2 at room temperature. In order to recrystallize the amorphized implanted region the samples were subjected to isochronal incremental annealings in air at temperatures between 400 and 640 °C. Photoluminescence (PL) and Rutherford backscattering spectrometry studies were performed for the as-implanted state and after each annealing step. The study of the 4I13/2 → 4I15/2 PL transition of Er3+ at 10 K reveals that Er centers in recrystallized KTP are similar to those observed in KTP:Er single crystals but differ from previous PL results in Er-implanted KTP. In the case of RTP a Rb loss at the surface is observed and the PL seems to be due to the overlapping emissions of Er centers similar to those of bulk RTP:Er crystals and those present in a Rb-deficient phase, like ErPO4.