Revelation of the Technological Versatility of the Eu(TTA)₃Phen Complex by Demonstrating Energy Harvesting, Ultraviolet Light Detection, Temperature Sensing, and Laser Applications

Abstract

We synthesized the Eu(TTA)3Phen complex and present herein a detailed study of its photophysics. The investigations encompass samples dispersed in poly(vinyl alcohol) and in ethanol in order to explore the versatile applicability of these lanthanide-based materials. Details upon the interaction between Eu, TTA, and the Phen ligands are revealed by Fourier transform infrared and UV-visible absorption, complemented by steady state and temporally resolved emission studies, which provide evidence of an efficient energy transfer from the organic ligands to the central Eu(3+) ion. The material produces efficient emission even under sunlight exposure, a feature pointing toward suitability for luminescent solar concentrators and UV light sensing, which is demonstrated for intensities as low as 200 nW/cm(2). The paper further promotes the complex's capability to be used as luminescence-based temperature sensor demonstrated by the considerable emission intensity changes of ∼4.0% per K in the temperature range of 50-305 K and ∼7% per K in the temeperature range 305-340 K. Finally, increasing the optical excitation causes both spontaneous emission amplification and emission peak narrowing in the Eu(TTA)3Phen complex dispersed in poly(vinyl alcohol) - features indicative of stimulated emission. These findings in conjunction with the fairly large stimulated emission cross-section of 4.29 × 10(-20) cm(2) demonstrate that the Eu(TTA)3Phen complex dispersed in poly(vinyl alcohol) could be a very promising material choice for lanthanide-polymer based laser architectures.

Thermosensitive Luminescent Lanthanide Complex with Two Photosensitized Ligands

“…Carboxy phosphine oxide (TPO), Eu(hfa) 3 (H 2 O) 2 , and Tb(hfa) 3 (H 2 O) 2 (TPO:Eu:Tb = 21:1:20, molar ratio) were added in methanol and refluxed at 333 K for 10 h (Fig. 1).…”

“…TPO (0.12 g, 0.3 mmol) was dissolved in methanol (2 ml) at 323 K and Gd(hfa) 3 (H 2 O) 2 (0.24 g, 0.3 mmol) in methanol (2 ml) was added. The precipitates were filtered, washed with methanol several times, and dried in vacuo.…”

“…The lanthanide complexes with characteristic narrow emission bands based on 4f-4f transitions have been regarded as attractive luminescent materials for use in lasers, (2,3) organic LEDs (4)(5)(6)(7) and bioimaging (8)(9)(10) applications. Efficient energy transfer from organic ligands to lanthanide ions, i.e., photosensitized energy transfer, is required to produce strong luminescence, because the 4f-4f transitions are Laporte forbidden, and as such have small absorption coefficients (ε < 10 M −1 cm −1 ).…”

Silver nanoparticles embedded hybrid organometallic complexes: Structural interactions, photo-induced energy transfer, plasmonic effect and optical thermometry

“…FTIR spectra of ETP contains large number of absorption peaks which are basically due to three constituent molecules in ETP namely phen, TTA and Eu-O, that has already been discussed in our previous report. 6 The fingerprint IR peak of TTA is observed at 1600 cm -1 which is due to asymmetric stretching mode of C=O. 37 Theonyl ring in the TTA structure points at 1413 cm -1 and 1540 cm -1…”

“…[24][25][26][27] In our previous report we have demonstrated the multi-functionality of red emitting Eu(TTA) 3 Phen (ETP) complexes, in which TTA molecules absorbed the UV-A as well as UV-B part of the radiation and transfer its energy to central Eu 3+ ion, whereas Phen protect it from the interaction with water molecules and thus provides stability to the complex. 6,28 Recently, Kumar et al have reported a strong green emitting Tb(ASA) 3 Phen (TAP) complex, in which acetylsalicylic acid (ASA) serves as the UV harvesting ligands. 27 In the present work, a hybrid complex (HC) by the mixing of ETP and TAP complexes has been prepared and their structural and optical properties have been investigated in details.…”