Enhanced photoluminescence dynamics, fluorescence decay and distinctive electrical properties of Eu2O3 nanoparticles decorated liquid crystal nanocomposites

Abstract

Herein, the reported work explored enhancement in photoluminescence, fluorescence decay, and electrical properties of rare-earth inorganic Europium oxide (Eu₂O₃) nanoparticles decorated 3b, 3c liquid crystal (LC) molecules. The textures of (E)-1-(4-pentoxy-3-fluorophenyl)-2-(4-butylphenyl) diazene (3b) @Eu₂O₃, (E)-1-(4-hexoxy-3-fluorophenyl)-2-(4-butylphenyl) diazene (3c) @Eu₂O₃ LC-nanocomposites (LC-NCs) showed birefringent mesophases with platelet/band-like and pebbles/marble-like structures, respectively. Steady-state photoluminescence revealed sharp/broad emission peaks at [551.8 nm, 553 nm (blue)]/422 nm (violet) for 3b@Eu₂O₃, 3c@Eu₂O₃ LC-NCs. Fluorescence decay lifetimes were between 0.231 ns–0.410 ns and 0.156 ns–0.528 ns, for 3b@Eu₂O₃ and 3c@Eu₂O₃ LC-NCs, respectively; and quantum yield was lower at the higher excitation wavelengths. Further, capacitance-voltage studies indicated symmetric permittivity of Eu₂O₃ on 3b, 3c LCs during heating cycle with applied voltage; while cooling mild reorientation at 6.3 V (positive) and 6.6 V (negative) was observed. Polarization vs. voltage studies unveiled no remnant polarization, and PFUND analysis revealed that polarization does not follow pulse rate and delay even at 10 V. Thus, the photoluminescent and electrical behavior of prepared LC-NCs pave the way for advancing photonic, and electro-optical devices.