Simultaneous enhancement upconversion luminescence and photocatalytic properties of BiOBr:Yb3+, Er3+ nanosheets by optically inert ions doping

Co-doped NaYF4:Yb/Er/Tm upconversion luminescent coating to enhance the efficiency of photovoltaic cells

“…The relationship between luminescence intensity and excitation power can be described by the following formula: I UC ∝ P n where I UC is the luminescence intensity, P is excitation power and n is the number of photons required for certain emission states. 42 By fitting the curves, it is calculated that the slope of the curves with the emission peak at 520 nm, 540 nm and 654 nm are close to 2, indicating that the upconversion luminescence is a two-photon process. The addition of Co 2+ ions did not change the two-photon process.…”