Defence Emmanuel de la Cruz-Pina: "Interaction and enhancement of photoluminescent properties of 0D and quasi-2D perovskites by plasmonic nanoparticles and piezoelectric films"
Promotors: First promotor: Prof M.I. Acuautla Meneses, Second promotor Prof J. Scherpen, Third promotor: Prof J. Reyes Esqueda
Abstract: This study explores how the interaction between plasmonic nanostructures and piezoelectric polymer films can influence the optical properties of small-dimension perovskites. The enhancement of photolu-minescence (PL) in quasi-2D perovskite films of (PEA)2 (MA)n-1PbnI3n+1 by plasmonic Ag nanoparticles (NPs) is meticulously explored. Additionally, the effects of interactions between piezoelectric polymer material and 0D quantum dots perovskites are studied to investigate possible mechano-optical effects and their potential applications. Through the exhaustive scanning of different coatings of Ag NPs, it was discerned that the enhancement in the PL intensity of perovskite films was intricately tied to the alignment between the maximum absorbance peak of Ag NPs and the excitation laser wavelength of 532 nm. Specifically, it was found that the highest amplification of PL intensity was achieved when the absorbance peak of the Ag NPs closely matched the laser wavelength. Furthermore, it was observed that the extent of PL intensity amplification also depended on the phase value, n, of the perovskite. Perovskites with high n-phase exhibited strong enhancement of PL intensity, with a maximum 7.8-fold amplification observed for samples with n = 10. Additionally, to investigate the interaction between perovskites and piezoelectric materials, polymeric piezoelectric films were fabricated, analyzed, and characterized using an energy harvesting system (EHS). The piezoelectric properties of the film were enhanced using a Corona Poling method to increase the output voltage generated when mounted in the EHS system. Once optimized, CsPbBr3 quantum dots were added onto the piezoelectric films via drop casting. The objective was to investigate the interaction and en-hancement of the optical and piezoelectric properties of these materials to advance the development of future piezo-optical devices. The piezoelectric and optical properties of these composites were studied under mechanical vibrations, UV light, and laser light exposure, aiming to identify mechano-optical effects exhibited by the composites. It was observed that the PL spectrum emitted by the composites was not affected by the piezoelectric potential enerated by the presence of the mechanical vibrations. However, increase in output voltage observed when the composites were simultaneously exposed to mechanical vibrations and UV light indicates a coupling between the piezoelectric and photovoltaic effects within the composite. These results suggest potential applications, such as the fabrication of multifunctional sensors and flexible high-efficiency piezo-phototronic solar cells.
Dissertation