Anomalous upconversion luminescence of SrMoO4:Yb3+/Er3+ nanocrystals by high excited state energy transfer

Infrared-to-visible upconversion emission of Er3+/Yb3+-codoped SrMoO4 phosphors as wide-range temperature sensor

“…These emission bands coincided well with earlier reports on Er 3+ /Yb 3+ -codoped SrMoO 4 nanomaterials, which were prepared by microwave-assisted metathetic method and sol-gel method[22,23]. The UC emission intensity increased gradually as the Yb 3+ ion concentration increased, reaching its optimum value when x = 0.05 due to the efficient ET from the Yb 3+ to Er 3+ ions.This concentration quenching is attributed to the ET between the nearest dopants (Yb 3+ and Er 3+ ions).…”

Highly precise FIR thermometer based on the thermally enhanced upconversion luminescence for temperature feedback photothermal therapy

“…The population of Er 3+ ions at 4 F 7/2 energy level mainly originate from the high excited state energy transfer (HESET) from Yb 3+ –MoO 4 2− dimer complex to Er 3+ ions. 30 Due to the small gap between 4 F 7/2 and 2 H 11/2 / 4 S 3/2 energy levels, Er 3+ ions populated at 4 F 7/2 energy level undergo a non-radiative relaxation process to 2 H 11/2 / 4 S 3/2 energy levels. The subsequent radiative transitions 2 H 11/2 / 4 S 3/2 → 4 I 15/2 produce intense green upconversion luminescence centered at 531 nm and 553 nm.…”

Optical Properties and Concentration Quenching Mechanism of Er3+ Heavy Doped Gd2(MoO4)3 Phosphor for Green Light-Emitting Diode

“…The n values indicate that two photons are involved in the green and red upconversion emissions. The possible upconversion mechanism for Gd 2 (MoO 4 ) 3 :Er 3+ phosphor is shown in Figure 4 b, and the detailed upconversion mechanism was discussed in our previous work [ 18 ]. The 2 H 11/2 / 4 S 3/2 and 4 F 9/2 levels of Er 3+ ions are populated via multiphonon relaxation from the 4 F 7/2 level, and the green and red upconversion emissions are observed.…”

“…All raw materials were purchased from Sinopharm. According to our previous work [ 18 ], Gd(NO 3 ) 3 ·6H 2 O (AR), (NH 4 ) 6 Mo 7 O 24 (AR), and Er(NO 3 ) 3 ·6H 2 O (AR) with precalculated concentrations were dissolved in deionized water, and citric acid (AR) was added to this solution. Subsequently, the pH level of the solution was adjusted to about 7 by adding an appropriate amount of ammonia (AR).…”