Shang, Xiaoying; Chen, Ping; Jia, Tianqing; Feng, Donghai; Zhang, Shian; Sun, Zhenrong; Qiu, Jianrong . (2015). Upconversion luminescence mechanisms of Er
<sup>3+</sup>
ions under excitation of an 800 nm laser. Phys. Chem. Chem. Phys., 17(17), 11481–11489.
doi:10.1039/C5CP00057B