A5025427529- Organic Light-Emitting Diodes Research
- Perovskite Materials and Applications
- Conducting polymers and applications
- Photochemistry and Electron Transfer Studies
- Quantum Dots Synthesis And Properties
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Porphyrin and Phthalocyanine Chemistry
- Free Radicals and Antioxidants
- Lanthanide and Transition Metal Complexes
- Solid-state spectroscopy and crystallography
- Nonlinear Optical Materials Studies
- Chalcogenide Semiconductor Thin Films
- 2D Materials and Applications
- Polyoxometalates: Synthesis and Applications
- Nanomaterials for catalytic reactions
- Catalytic Processes in Materials Science
- Silicone and Siloxane Chemistry
- Layered Double Hydroxides Synthesis and Applications
- Synthesis and Properties of Aromatic Compounds
- Thermal Expansion and Ionic Conductivity
- Carbon and Quantum Dots Applications
- Metal complexes synthesis and properties
- Nonlinear Optical Materials Research
- Photochromic and Fluorescence Chemistry
University of Aveiro
2022-2025
Universidade Estadual de Campinas (UNICAMP)
2014-2022
Energy Institute
2019
Pontifícia Universidade Católica de Campinas
2018
Engineering 2D/3D perovskite interfaces is a common route to realizing efficient and stable solar cells. Whereas 2D perovskite's main function in trap passivation has been identified confirmed here, little known about its interface properties under thermal stress, despite being one of the factors that induces device instability. In this work, we monitor response two typical cycle by situ X-ray scattering. We reveal upon heating, crystalline structure undergoes dynamical transformation into...
ESIPT for white-light generation from all-solution-processed OLEDs.
Carbon dots (C-dots) possess the attractive properties of high stability, low toxicity, good water solubility, simple synthetic routes as well size and excitation-dependent photoluminescence (PL).The aim this work was to synthesize photoluminescent C-dots by hydrothermal method using acerola fruit (Malpighiaemarginata) a row material, since contains large number organic molecules. Studies about optimal synthesis conditions were performed, where these molecules converted into carbonization at...
OLEDs with CVD graphene anodes on cellulose substrates demonstrate an alternative for environmentally friendly, transparent and flexible devices.
In this study, two salicylidene ligands, N,N′-bis(salicylidene)-1,2-phenylenediamine and N,N′-bis(salicylidene)-4,5-diaminopyrimidine, their respective aquo-zinc(II) coordination compounds were synthesized. Their characterization was performed by FTIR, proton carbon NMR, elemental analysis, mass spectroscopy, cyclic voltammetry. Crystal structures of the ligands determined monocrystal X-ray diffraction. The photoluminescent properties under photostationary conditions indicate that ligand...
Hybrid organic and inorganic perovskite solar cells lack long‐term stability, this negatively impacts the widespread application of emerging promising photovoltaic technology. Herein, aiming to increase stability films based on CH 3 NH PbI deeply understand formation 2D structures, solutions alkylammonium chlorides containing 8, 10, 12 carbons are introduced during spin‐coating surface 3D leading in situ structures. It is possible identify chemical formulae some structures formed by X‐ray...
Two derivatives salicylidene-4,6-(dimethylamino)pyridine (KM1) and salicylidene-5-bromo-4,6-(dimethylamino)pyridine (KM2) reactive to excited-state intramolecular proton transfer (ESIPT) were synthesized as a strategy produce white light diodes with small organic molecules. White color resulted from the presence of both normal (420 nm) tautomeric (550–580 species emission. The photophysical features N* T* unveiled in solution solid state. ESIPT mechanism revealed influence near attack...
Abstract 2D metal halide semiconductors have been intensively studied in the past few years due to their unique optical properties and potential for new‐generation photonic devices. Despite large number of recent works, this class materials is still need further understanding complex structural characteristics. In work, a molecular‐level explanation dual band emission (C 4 H 9 NH 3 ) 2 PbI its bulk form presented, demonstrating that feature caused by strong exciton–phonon coupling....
In this study, the photophysical properties of N-salycilidene-5-chloroaminopyridine were evaluated. This molecule presented dual emission from keto* and enol* species, depending on solvent used (DMSO or methanol in absence presence trifluoroacetic acid). was synthesized through a dehydration reaction salicylaldehyde under sonication characterized using FTIR, cyclic voltammetry, mass spectrometry, single-crystal X-ray diffraction, yielding molecular structure. Theoretical calculations...
Excited state intramolecular proton transfer (ESIPT) in a novel salicylidene sal-3,4-benzophen chromophore is studied by white-light femtosecond pump–probe and time-resolved fluorescence techniques, as well theoretical calculations under the time dependent density functional theory framework. We show that when (in enol form) excited (at 390 nm) to cis-enol* form, it quickly converted hot cis-keto* (hK*) form due fast ESIPT process (τESIPT = 150 fs). Subsequently, cooling from cold (cK*)...
Abstract CsPbX 3 perovskite nanoplates (PNPLs) were formed in a synthesis driven by SnX 4 (X=Cl, Br, I) salts. The role played these hard Lewis acids directing PNPL formation is addressed. Sn 4+ disturbs the acid–base equilibrium of system, increasing protonation rate oleylamine and inducing anisotropic growth nanocrystals. cations influence reaction dynamics owing to complexation with molecules. By monitoring photoluminescence excitation (PL) spectra PNPLs grown at different temperatures,...
In this work, we verified that light induces a dynamic equilibrium between ligands and the inorganic surface in amine-free perovskite nanocrystals, demonstrated oleylphosphate can improve photostability of cesium lead bromide nanocrystals.
Silver nanoparticles and zinc hydroxide-layered hybrid materials (AgNPs/ZHL) have been successfully developed as efficient catalysts for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with sodium borohydride.A facile rapid visible-light assisted green route was used deposition silver (AgNPs) on external surface ZHL material.The resulting AgNPs/ZHL hybrids contained AgNPs spherical morphology uniform size distribution.Moreover, compounds exhibited excellent catalytic...
Ruddlesden–Popper organic lead halides (RPOLHs) are in the material science spotlight because of their remarkable optoelectronic properties, tailorable compositions, and improved ambient stability over three-dimensional perovskite analogues. In this report, we introduce a new synthesis method for RPOLHs with general composition L2[FAPbI3]n−1PbI4 [L = butylammonium (BA) or benzylammonium (BZA), FA formamidinium, n 1 2]. Our yields polycrystalline materials useful thin-film fabrication...
This paper report on the excited-state (ESA) and two-photon absorption (2PA) features of two novel salicylidene compounds: N,N′-bis(salicylidene)-1,2-phenylenediamine (salophen) its Zn(II) coordination compound ([Zn(salophen) (OH2)]). The molecular structure salophen is a tetradentated ligand with iminic phenolic bonding sites, allowing metal ions such as zinc(II) forming [Zn(salophen) (OH2)]. According to our data, complex modifies ESA 2PA spectrum ligand, increasing significantly...
Many multication perovskites for highly stable and efficient solar cells benefit from rubidium iodide introduced in the precursor solution. It is well-known that Rb+ influences positively optoelectronic mobility properties has a direct effect upon crystallization halide homogenization. As often incorporated by adding RbI solution, it can be difficult to distinguish influence of I– separately. Herein, we report postpassivation methylammonium-free (CsFA) perovskite films with butyrate (RbBu)....
In situ GIWAXS experiments reveal that the presence of RGO decreases formation rate perovskite, increases grain size, and improves stability solar cells.
The photo- and electroluminescent properties of single-layer two-component blends composed one blue emitter polymer green were studied. emitter, poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(9,9-di-{5'-pentanyl}-fluorenyl-2,7-diyl)] (PFOFPen), was used as the matrix, poly[(9,9-dihexylfluorenyl-2,7-diyl)-alt-co-(bithiophene)] (F6T2), guest. F6T2 content in varied from 0.0075 wt % to 2.4 %. Remarkable differences observed between (EL) photoluminescent (PL) spectra these blends, which indicated...