BROADBAND QUANTUM CUTTING IN ZnO/Yb(Er)F3 OXY-FLUORIDE NANOCOMPOSITE PREPARED BY THERMAL OXIDATION METHOD

Abstract

Yb(Er)F3 nanoparticles absorbed with ZnO sheet were prepared via two-step co-precipitation method followed with thermal oxidation. In the ZnO / Yb(Er)F3 composite phosphor, ZnO can efficiently absorb ultraviolet photons of 250–380 nm and transfer its absorbed photon energy to Er 3+ ions in fluoride particles. A followed quantum cutting between Er 3+- Yb 3+ couples in the fluoride takes place, down-converting an absorbed ultraviolet photon into two photons of 650 nm and 980 nm radiations. The composite phosphor combines the wide wavelength absorption range and high absorption cross-section of ZnO with high quantum cutting efficiency of Er 3+- Yb 3+ co-doped fluoride, showing potential application in the enhancement of Si solar cell efficiency.