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Dr. Yolanda Salinas

Dr. Yolanda Salinas

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Overview

Dr. Yolanda Salinas, Priv.-Doz. Dr. (Assistant Professor) at the Johannes Kepler University Linz, Institute of Polymer Chemistry (ICP).

Water-enhanced colloidal perovskite nanoparticles for the formation of highly fluorescent thin films.

Summary:

Colloidal quantum dots, particularly hybrid organic-inorganic lead halide perovskites, are next generation candidates as imaging tools in biology and medicine, and also for lighting and optoelectronic displays. We have recently used a-amino based ligands to tailor emission within a narrow bandwidth, as well as remarkable high photoluminescence quantum yields (PLQYs). Interestingly, the presence of water molecules forms highly mobile species leading to significant enhancement of MAPbBr3 and FAPbBr3 perovskite nanoparticles, as colloidal solutions and thin films.

Abstract:

Colloidal quantum dots can be ideal candidates as imaging tools in biology and medicine, but also for lighting and optoelectronic displays. In this sense, hybrid organic-inorganic lead halide perovskites, prepared as nanoparticles, have emerged as novel ionic semiconductor materials to be applied to optoelectronic and photonic devices due to their highly emitting features. Generally, the synthesis of colloidal nanoparticles is followed by the ligand-assisted reprecipitation (LARP), which is a powerful tool to fine-tune nanostructured perovskite features targeted for specific applications.1 This method is generally selected for preparing nanoparticles since it is a cost-effective and ease to scale-up synthetic pathway, which only requires affordable equipment and convenient operational temperatures. We have recently optimized this method by deeply studying a variety of conditions which could influence on the formation of methylammonium lead bromide (MAPbBr3) perovskite nanoparticles, using different types of ligands containing a-amino groups (Fig. 1a).2 A tailored emission within a narrow bandwidth, as well as a remarkable high photoluminescence quantum yields (PLQYs) were achieved by merging a diversity of nature-inspired capping agents while employing the ligand-assisted precipitation technique. The choice of the solvent system, the precipitation temperature, and the concentration of precursor chemicals were demonstrated to have a crucial role on the resulting optical properties of the colloidal solutions affecting lately on the resulting morphology.3 Interestingly, the presence of water molecules was assumed to form highly mobile species leading to the enhancement of controlling the perovskite lattice growth, causing shifts in emission wavelength due to quantum confinement effects4. Therefore, the addition of water demonstrated to remarkably help to tailor the optical properties of MAPbBr3 and formamidinium lead bromide (FAPbBr3) perovskite nanoparticles stabilized by amino acids-based ligands, as colloidal solutions and thin films (Fig. 1b-c). The resulting spherical and highly crystalline sub-10 nm nanoparticles exhibited an emission within a narrow bandwidth of the visible spectrum and a photoluminescence with an extraordinary quantum yield close to 100%.5 Our results and investigations suggested that upon further optimization of their synthesis to control their size, or even by growing or embedding those into an optically clear polymeric matrix could further enhance their optical properties, hence improving the production and stability of thin films. In general, they are envisioned as the next generation of active nanostructured candidates for the fabrication of future light emitting diodes (LEDs), photodetectors, and lasers.

 

Figure 1. a) General structure of PNPs showing the perovskite core decorated on the surface with the ligands (e.g., hexanoic acid and t-boc-L-Lysine); b) colloidal solutions of MAPbBr3 perovskite nanoparticles and c) thin solid films made by centrifugal casting of MAPbBr3 and FAPbBr3 colloidal solutions, with different amounts of water as additive.

  1. Schmidt, L. C.; Pertegás, A.; González-Carrero, S.; Malinkiewicz, O.; Agouram, S.; Mínguez Espallargas, G.; Bolink, H. J.; Galian, R. E.; Pérez-Prieto, J., Nontemplate Synthesis of CH3NH3PbBr3 Perovskite Nanoparticles. Journal of the American Chemical Society 2014, 136 (3), 850-853.
  2. Jancik Prochazkova, A.; Scharber, M. C.; Yumusak, C.; Jančík, J.; Másilko, J.; Brüggemann, O.; Weiter, M.; Sariciftci, N. S.; Krajcovic, J.; Salinas, Y.; Kovalenko, A., Synthesis conditions influencing formation of MAPbBr3 perovskite nanoparticles prepared by the ligand-assisted precipitation method. Scientific Reports 2020, 10 (1), 15720.
  3. Jancik Prochazkova, A.; Demchyshyn, S.; Yumusak, C.; Másilko, J.; Brüggemann, O.; Weiter, M.; Kaltenbrunner, M.; Sariciftci, N. S.; Krajcovic, J.; Salinas, Y.; Kovalenko, A., Proteinogenic Amino Acid Assisted Preparation of Highly Luminescent Hybrid Perovskite Nanoparticles. ACS Applied Nano Materials 2019, 2 (7), 4267-4274.
  4. Jancik Prochazkova, A.; Salinas, Y.; Yumusak, C.; Scharber, M. C.; Brüggemann, O.; Weiter, M.; Sariciftci, N. S.; Krajcovic, J.; Kovalenko, A., Controlling Quantum Confinement in Luminescent Perovskite Nanoparticles for Optoelectronic Devices by the Addition of Water. ACS Applied Nano Materials 2020, 3 (2), 1242-1249.
  5. Jancik Prochazkova, A.; Mayr, F.; Gugujonovic, K.; Hailegnaw, B.; Krajcovic, J.; Salinas, Y.; Brüggemann, O.; Sariciftci, N. S.; Scharber, M. C., Anti-Stokes photoluminescence study on a methylammonium lead bromide nanoparticle film. Nanoscale 2020, 12 (31), 16556-16561.

 

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