Enhancement of ultraviolet upconversion in Yb3+ and Tm3+ codoped amorphous fluoride film prepared by pulsed laser deposition

Abstract

Zn 0.3 Al 0.25 Pb 0.3 Li 0.098 Yb 0.1 Tm 0.002 F 2.354 amorphous fluoride film was prepared by pulsed laser deposition. Ultraviolet and blue up-conversion emissions were observed under infrared excitation at 978 nm. In comparison with the upconversion of the target, the ultraviolet emissions are enhanced greatly. The enhancement is attributed to a decrease of the Judd-Ofelt parameter ⍀ 2 induced by pulsed laser deposition, which precludes the transition rate from 3 F 2 to 3 F 4 and enhances the energy transfer process and populates the 1 D 2 level: 3 F 2 → 3 H 6 (Tm 3ϩ): 3 H 4 → 1 D 2 (Tm 3ϩ).

Sensitized high-order ultraviolet upconversion emissions of Gd3+ by Er3+ in NaYF4 microcrystals

“…As one of the available approaches for achieving the short-wavelength laser radiation, frequency UC based on certain rare-earth ions (RE 3+ ) in different matrix have been investigated widely in the past two decades. However, most studies about UC emissions of RE 3+ ions have focused on the visible region, and only a few groups reported strong UV UC emissions [5][6][7][8][9][10]. Consequently, synthesizing the intense UV luminescent materials and investigating UV UC emission mechanism are the most important tasks for researchers to develop UV UC solid-state lasers.…”

Upconversion from fluorophosphate glasses prepared with NaYF4:Er3+,Yb3+ nanocrystals

“…[1][2][3][4][5][6][7][8][9][10] The codoping with Er 3+ and Yb 3+ allows the conversion of NIR radiation usually to green and red emissions due to the absorption of two or more photons. As Yb 3+ ion possesses a high absorption cross-section and also a broad absorption band between 850 and 1080 nm compared to the weak absorption of Er 3+ ions, it absorbs the pump energy which is then transferred to the Er 3+ ion as ref.…”

Characterisation and luminescence studies of Tm and Na doped magnesium borate phosphors

“…It is well known that trivalent Tm is split into different complicated energy level schemes because of a strong distortion and deviation from L-S coupling although emission occurs due to the intra 4f electronic transitions which is shielded by outer levels from the crystal field. Consequently, emission lines of Tm cover a region including UV, visible, and infra-red (IR) emission (Qin et al, 2003). The sodium ions act as a charge compensator and they do not introduce any emission.…”