Gold Raspberry Shell Grown onto Nonspherical Lithium Niobate Nanoparticles for Second Harmonic Generation and Photothermal Applications

• DOI: 10.1002/ppsc.202200093
• Publication Date: 2022-08-12T14:53:23Z
• Authors: Rachael Taitt; Mathias Urbain; Kévin Bredillet; Zacharie Behel; Giacomo Ceccone; Jorge Bañuls‐Ciscar; Sandrine Beauquis; Yannick Mugnier; Pierre‐François B...; Ronan Le Dantec; Yann Chevolot; Virginie Monnier
• Keywords: plasmon; [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics]; second harmonic generation; photothermia; lithium niobate nanoparticles; [CHIM.MATE]Chemical Sciences/Material chemistry; gold shell; 540; 530; 7. Clean energy

Abstract Nanoparticles (NPs) containing a lithium niobate (LiNbO 3 ) core and gold shell are prepared using combination of seeded‐growth layer‐by‐layer approaches. The method includes first the surface charge reversal with branched polyethyleimine, second, electrostatic binding seeds, third, successive reduction steps chloride onto gold‐seeded LiNbO NPs for progressive surface‐directed growth shell. influence three synthesis parameters, namely, pH, initial density seeds covering core, concentration, on NPs’ characteristics (structural properties, plasmon band, charge, hydrodynamic diameter) is studied. progress investigated by X‐ray photoelectron spectroscopy time‐of‐flight secondary ion mass spectrometry. In addition, it shown that LN@Au core–shell can emit second harmonic generation signal when excited femtosecond laser. Finally, photothermal properties studied, showing an increase temperature 8.6 °C upon infrared excitation, estimated light‐to‐heat conversion efficiency 40% specific absorption rate 8000 W g −1 .