Open AccessPhonon-assisted upconversion charging in Zn_3Ga_2GeO_8:Cr^3+ near-infrared persistent phosphor
Author(s) -
Feng Liu,
Yafei Chen,
Yan Liang,
Zhengwei Pan
Publication year - 2016
Publication title -
optics letters/optics index
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.41.000954
Subject(s) - photon upconversion , phosphor , excitation , luminescence , materials science , persistent luminescence , phonon , optoelectronics , infrared , laser , photon , optics , physics , condensed matter physics , thermoluminescence , quantum mechanics
We report a new phonon-assisted upconversion excitation design that enables the excitation energy to be lower than the persistent luminescence emission energy in persistent phosphors. We demonstrate this upconversion excitation concept in Zn3Ga2GeO8:Cr(3+) near-infrared persistent phosphor by achieving Cr(3+) 700 nm persistent emission using 800 or 980 nm laser diode excitation. Depending on the sample temperature, the excitation photon energy can be tuned, and the persistent luminescence intensity can be adjusted. Depending on the excitation power, the upconversion trap filling process involves either one photon (for filling low-energy traps) or two photons (for filling high-energy traps). Our research provides a major step toward manipulating the electronic excitation in persistent luminescence, which has implication for many applications.