Lanthanide(III)-Incorporating Polysiloxanes as Materials for Light-Emitting Devices

Abstract

Light-excited flexible and self-healing luminescent polymers have attracted extensive attention for developing advanced color-emitting films. Luminophores on the base of lanthanide(III)-incorporating polysiloxanes exhibit a high photoresponse and can be applied for controlled color lighting in flexible device applications. We present red-, green-, and blue-emitting Eu 3+ , Tb 3+ , and Tm 3+ -bipyridinedicarboxamide-co-polydimethylsiloxanes (Ln-Bipy-PDMS) produced with a two-step procedure of polycondensation and complexation. Bipyridinic ligands provide formation of coordinatively saturated complexes of lanthanide ions and strong photoluminescence (PL) in the case of Eu 3+ and Tb 3+ . The thin Ln-Bipy-PDMS films are studied as ultraviolet-light converters, which can be mechanically stacked one above another to achieve the desired color. We demonstrate that these stacks can have intense PL in the spectral range from green to yellow and red. Due to the structural features, Ln-Bipy-PDMS also demonstrate a relatively high tensile (approximately 1.5 MPa) and elongation at break (approximately 185%) and non-autonomous self-healing on heating. The self-healing properties of Ln-Bipy-PDMS enable the stacking of films into monoliths with the required color of PL. Such systems do not require any synthesis stages, and a one-healed monolith film possesses two luminescence colors.

Unprecedented toughness in transparent, luminescent, self-healing polymers enabled via hierarchical rigid domain design

“…3c and Table S2, ESI †). [11][12][13][21][22][23][24][25][26][27] Even compared with the non-luminescent strong and tough selfhealing elastomers reported in the literature, the toughness of our materials is still unprecedented (Fig. 3d).…”

Structural Features of Eu3+ and Tb3+-Bipyridinedicarboxamide Complexes

“…To the best of our knowledge, the photoluminescent properties of lanthanide(III) coordinatively saturated complexes with BDCA have never been studied. The only known similar lanthanide(III)-incorporating polymer-metal complexes (PMCs) are based on polydimethylsiloxanes functionalized by tetradentate bipyridine, functioning as ligands toward Eu 3+ and Tb 3+ [11]. Previously, we designed PMCs of Eu 3+ and Tb 3+ -bipyridinedicarboxamide-co-polydimethylsiloxanes, which exhibit a high photoresponse and are applied as flexible, self-healing, and color-tunable photoluminophores in flexible device applications [11].…”

“…The only known similar lanthanide(III)-incorporating polymer-metal complexes (PMCs) are based on polydimethylsiloxanes functionalized by tetradentate bipyridine, functioning as ligands toward Eu 3+ and Tb 3+ [11]. Previously, we designed PMCs of Eu 3+ and Tb 3+ -bipyridinedicarboxamide-co-polydimethylsiloxanes, which exhibit a high photoresponse and are applied as flexible, self-healing, and color-tunable photoluminophores in flexible device applications [11]. The main advantage of these PMCs is that they can be mechanically stacked one above another to achieve the desired emission color in the spectral range from green to yellow and red.…”

“…Among a great range of photoluminescent lanthanide complexes, europium(III) and terbium(III) organic luminophores are broadly investigated, since Eu 3+ and Tb 3+ cations have intense pure red and green emission in the visible region [10]. These emission colors are the components of the RGB system [11] that could be used as a light converter for light-emitting diodes and colored displays fabrication.…”

“…Therefore, the use of low-molecular-weight BDCA ligand instead of polysiloxane bipyridine-containing ligand can increase QY compared to ref. [11]. Hence, the development of methods for the synthesis of luminescent complexes based on Eu 3+ , Tb 3+ , and BDCA, with high QY, is a challenging task.…”