Upconversion luminescence and kinetics in Er3+:YAlO3 under 652.2 nm excitation

Ultraviolet and visible upconversion properties of Er3+ in YAlO3 were investigated following 652.2 nm excitation of the multiples 4F9/2. The luminescence and excitation spectra were recorded. Ultraviolet (326–342 and 354–359 nm), violet (405–420 nm), blue (436–442 nm) and green (525–575 nm) upconversion and infrared downconversion luminescence were simultaneously observed. The intense green luminescence corresponds to the emissions from the thermal coupled 4S3/2 and 2H11/2 bands and 2G9/2 level. Energy transfer upconversion processes were proposed to explain the upconversion phenomena. The luminescence kinetics was discussed in detail by the analyses of fluorescence decay curves.