Notes on thermometric artefacts by Er3+ luminescence band interference
in: Journal of Luminescence (2021)
Optical thermometry based on the intensity ratio of the 2H11/2 → 4I15/2 (525 nm) and 4S3/2 → 4I15/2 (545 nm) emission of Er3+ provides a powerful tool for microscale temperature sensing. Crystalline β-NaYF4:Er,Yb is an excellent thermometry material for green upconversion emission upon NIR laser excitation. However, interfering 2H9/2 → 4I13/2 emission is observed around 555 nm for continuous-wave laser excitation intensities above 10 W/ cm2. In this study, the green Er3+ emission bands are characterized and it is demonstrated how the true sample temperature is determined circumventing possible artefacts.