Effects of post heat treatment on near infrared photoluminescence of YAG:Yb3+ nanoparticles synthesized by glycothermal method

•YAG:Yb3+ nanoparticles of ca. 10 nm are prepared by glycothermal method at 300 °C.•1029 nm near infrared emission takes place under 940 nm near infrared excitation.•Emission and excitation correspond to 2F5/2→2F7/2 transition of Yb3+.•Subsequent heat treatment causes crystallite growth and elimination of hydroxyl groups, resulting in enhancement of near infrared emission.

Influence of post heat treatment on particulate, structural, surface, and optical properties of YAG:Yb3+ nanoparticles prepared by glycothermal method is studied to understand factors for determining photoluminescence intensity. Characterization is performed on electron microscopy, X-ray diffractometry, infrared absorption spectroscopy, and optical measurements. Near infrared emission under 940 nm near infrared excitation is observed at 1029 nm corresponding to 2F5/2→2F7/2 transition of Yb3+. Subsequent heat treatment causes crystallite growth and elimination of hydroxyl groups, resulting in an enhancement of the near infrared emission.