Green to red and NIR tunable luminescence in heavily Er3+‐doped tellurite glasses via selective energy transfer mechanism

Abstract

AbstractHere, we select simple Er3+‐doped tellurite glass as model system to systematically explore the up‐conversion, down‐shifting mechanisms with different excitations (980 and 447 nm), respectively. We observe for the first time, to the best of our knowledge that tunable photo‐luminescence occurs from green to red and NIR region, rather than merely from the long‐accepted green to red region. Direct evidence of selective energy transfer mechanism is expounded in detail, and its potential applications are demonstrated. In addition, we provide evidence that the cross‐relaxation process between dopant ions can enhance photo‐luminescence in Er3+ doped tellurite glasses with high dopant concentrations, whereas the crucial reason for emission decrease is the energy loss long‐distance energy migration. These fundamental insights into the photophysical processes in heavily doped photonic glasses will broaden the applications of rare‐earth‐doped materials ranging from optical communications to medical imaging.