Effect of Fluorination on the Radiative Properties of Er³⁺ Organic Complexes: An Opto-Structural Correlation Study

Abstract

It is expected that fluorinated organic erbium(III) complexes, of interest for optical applications at λ = 1.5 μm, have improved performance with respect to hydrogenated counterparts. However, the intrinsic radiative properties (including the absorption/emission line strengths) of organic Er 3+ complexes have not been systematically studied and compared up to date. This has precluded the observation of opto-structural correlations as well as a proper characterization of the infrared f-f transitions and thus a lack of meaningful figures for the optical efficiency of these materials at the 1.5 μm emission. We have performed a complete opto-structural correlation study of the oscillator strengths of the f-f transitions of hydrogenated and fluorinated organic erbium(III) complexes, including a Judd-Ofelt analysis. The Judd-Ofelt analysis on the crystals has allowed the study of the interdependence of the chemical nature, structure, and spectroscopic behavior. We observe clear trends that can help the design and understanding of these important infrared emitters for phosphor and opto-electronic applications.

Field-induced single-ion magnetic behaviour in a highly luminescent Er3+ complex

“…The experimental diffractogram shows a background higher for low theta angles as expected from the diffuse scattering of X-Rays by glass and air, a common characteristic when using rotating capillaries in a Debye-Scherrer geometry. Powder diffraction shows that all the material synthesized in crystalline form corresponds to the same structure as the small single crystals reported for single-crystal X-ray diffraction by Ye et al [24]. …”

High sensitization efficiency and energy transfer routes for population inversion at low pump intensity in Er organic complexes for IR amplification

“…For the rate equations only three levels are taken into account: the ground state ( 4 I 15/2 ) of the Er 3+ , (with a population of N 0 ), the first excited state ( 4 I 13/2 ) of the Er 3+ , (with a population of N 1 ), and the third excited state ( 4 F 9/2 ) of the Er 3+ , (with a population of N 2 ). The transition rate, A 20 , ( 4 F 9/2 to 4 I 15/2 ) was taken as 1000 s −1 and was obtained from a Judd-Ofelt calculation for Er(F-TPIP) 3 25 . The transition rate A 21 ( 4 F 9/2 to 4 I 13/2 ) (τ 21  = 0.5 µs) was measured directly from the rise time for the 4 I 13/2 to 4 I 15/2 transition when the 4 F 9/2 level was excited directly using an ~5 ns pulse at 655 nm from an OPO.…”

“…The value of A 10 we used in our model was therefore determined from a linear fit to this average lifetime and hence was a function of the excitation intensity. The pump rate, R P , is given by the absorption cross-section for the 4 I 15/2 to 4 F 9/2 (σ abs  = 1.3 × 10 −21  cm 2 ) multiplied by the photon flux density (φ) 25 . The fit to the 655 nm data only has a single scaling factor in it to convert the emission rate from the model ( N 1 A 10 ) into the arbitrary units of the intensity measured by the photomultiplier.…”

Synthesis and investigation of an erbium-containing photosensitive polymer

“…A growing demand exists for low-cost near-infrared (NIR) light sources for communications [3][4][5] . In recent years, Er-doped waveguide amplifiers (EDWAs) have aroused significant research attention in the field of telecommunications because the infrared emission 25 properties of Er 3+ ion at around 1530 nm is suitable for long distance communications 6-10 .…”

“…2, 2´-Azobisisobutyronotrile (AIBN), recrystallized freshly, was used as free-radical initiator. 5 Copolymers were obtained by free-radical polymerization of dilute monomer solutions. All of the solvents were used after purification according to conventional methods.…”