Simultaneous enhancement of upconversion luminescence and photoelectric effect in NaYF4:Yb3+/Tm3+/Zr4+ tri-doped microcrystals

β-NaYF4: Yb3+/Tm3+/Zr4+ microcrystals are synthesized by a facile hydrothermal route. The up-conversion (UC) luminescence and photoelectric effects are enhanced simultaneously with the introduction of Zr4+ ions under IR excitation. With the Tm3+ ions fluorescence spectra under 980 nm excitation, the blue and red emissions reached the highest intensity in the case of 4 mol% Zr4+ doping. Taking the advantage of Zr4+ stimulates the free electrons transfer from the valence band (VB) to the conduction band (CB) in β-NaYF4:Yb3+/Tm3+/Zr4+ microcrystals, the photocurrent reached the highest intensity in the case of 4 mol% Zr4+ doping at 780 nm excitation. The β-NaYF4: Yb3+/Tm3+/Zr4+ microcrystals with both enhanced UC luminescence and photoelectric properties are highly potential to contribute in photovoltaic and infrared sensors application.