Controlling disorder in host lattice by hetero-valence ion doping to manipulate luminescence in spinel solid solution phosphors

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2018,（12）
• 页码范围: 1624-1629
• 页数: 6页
• 语种: 英文

摘要

Phosphor materials have been rapidly developed in the past decades.Developing phosphors with desired properties including strong luminescence intensity and long lifetime has attracted widespread attention.Herein,we show that hetero-valence ion doping can serve as a potent strategy to manipulate luminescence in persistent phosphors by controlling disorder in the host lattice.Specifically,spinel phosphor Zn(Ga1-xZnx)(Ga1-xGex)O4∶Cr is developed by doping ZnGa2O4∶Cr with tetravalent Ge4+.Compared to the original ZnGa2O4∶Cr,the doped Zn(Ga1-xZnx)(Ga1-xGex)O4∶Cr possesses significantly enhanced persistent luminescence intensity and prolonged decay time.Rietveld refinements show that Ge4+ enters into octahedral sites to substitute Ga3+,which leads to the co-substitution of Ga3+ by Zn2+ for charge compensation.The hetero-valence substitution of Ga3+ by Ge4+ and Zn2+ enriches the charged defects in Zn(Ga1-xZnx)(Ga1-xGex)O4∶Cr,making it possible to trap large amounts of charge carriers within the defects during excitation.Electron paramagnetic resonance measurement further confirms that the amount of Cr3+ neighboring charged defects increases with Ge4+ doping.Thus charge carriers released from defects can readily combine with the neighboring Cr3+ to produce bright persistent luminescence after excitation ceases.The hetero-valence ion doping strategy can further be employed to develop many other phosphors and contributes to lighting,photocatalysis and bioimaging.