Národní úložiště šedé literatury Nalezeno 2 záznamů.  Hledání trvalo 0.00 vteřin. 
Synthesis and Study of Nano-Structured Perovskites for Applications in Organic Electronics
Jančík Procházková, Anna ; Kuřitka, Ivo (oponent) ; Částková, Klára (oponent) ; Krajčovič, Jozef (vedoucí práce)
Diversity and unique properties, such as exceptionally high photoluminescence quantum yields (PLQYs), predetermine metal halide perovskite nanoparticles (PNP) to be applied in optoelectronic and photonic devices. In this work, nature-inspired capping agents were employed not only for the PNP stabilization but also for modifying their surface to broaden the functionality of the resulting material. In the very beginning, a ligand-assisted precipitation technique was optimized for the preparation of the PNP. Here, adamantane-1-amine (AdNH2) alongside hexanoic acid (HeA) were chosen as capping agents for nanoparticles stabilization and passivation. It was demonstrated that the choice of the solvent system and the precipitation temperature have a crucial effect on the resulting optical properties of the colloidal solutions. Simultaneously, the influence of concentration of precursor chemicals on the resulting morphology and optical properties was investigated. Also, different carboxylic acids were tested as capping agents among AdNH2 and the colloidal stability of the resulting colloidal solutions was evaluated. To demonstrate the diversity of the ligand-assisted precipitation technique of PNP preparation, L-lysine and L-arginine were employed initially for the surface passivation. As a result, colloidal solutions with emission within a narrow bandwidth of the visible spectrum and remarkable photoluminescence quantum yield (PLQY) close to 100% were obtained. Blocking -amino group of L-lysine by tert-butoxycarbonyl group suggested preferential binding of the side chain of L-lysine to the perovskite core. Furthermore, defined amounts of water were added into the precursor solutions which caused shifts of emission spectra due to quantum confinement effects. Water molecules were assumed to form highly mobile species leading to the enhancement of controlling the perovskite lattice growth. Merging perovskite nanomaterials with peptides are expected to pave a way to the new class of materials possessing exceptional optoelectronic properties alongside self-assembly and sensing abilities. As a proof-of-concept, a cyclic(RGDFK) pentapeptide was used for PNP stabilization. However, peptides are known for their sensitivity to their environment. Therefore, peptide nucleic acid (PNA) was used for PNP stabilization as a robust artificial analogue for deoxyribonucleic acid (DNA). Here, optical properties of thymine-based PNA monomer and trimer stabilized PNP were studied. Additionally, the sensing ability of the PNA ligand for adenine moiety was demonstrated by photoluminescence quenching via charge transfer. We envision that combining the unique tailored structure of PNA and the prospective optical features of PNP could expand the applications especially in the field of optical sensing devices.
Synthesis and Study of Nano-Structured Perovskites for Applications in Organic Electronics
Jančík Procházková, Anna ; Kuřitka, Ivo (oponent) ; Částková, Klára (oponent) ; Krajčovič, Jozef (vedoucí práce)
Diversity and unique properties, such as exceptionally high photoluminescence quantum yields (PLQYs), predetermine metal halide perovskite nanoparticles (PNP) to be applied in optoelectronic and photonic devices. In this work, nature-inspired capping agents were employed not only for the PNP stabilization but also for modifying their surface to broaden the functionality of the resulting material. In the very beginning, a ligand-assisted precipitation technique was optimized for the preparation of the PNP. Here, adamantane-1-amine (AdNH2) alongside hexanoic acid (HeA) were chosen as capping agents for nanoparticles stabilization and passivation. It was demonstrated that the choice of the solvent system and the precipitation temperature have a crucial effect on the resulting optical properties of the colloidal solutions. Simultaneously, the influence of concentration of precursor chemicals on the resulting morphology and optical properties was investigated. Also, different carboxylic acids were tested as capping agents among AdNH2 and the colloidal stability of the resulting colloidal solutions was evaluated. To demonstrate the diversity of the ligand-assisted precipitation technique of PNP preparation, L-lysine and L-arginine were employed initially for the surface passivation. As a result, colloidal solutions with emission within a narrow bandwidth of the visible spectrum and remarkable photoluminescence quantum yield (PLQY) close to 100% were obtained. Blocking -amino group of L-lysine by tert-butoxycarbonyl group suggested preferential binding of the side chain of L-lysine to the perovskite core. Furthermore, defined amounts of water were added into the precursor solutions which caused shifts of emission spectra due to quantum confinement effects. Water molecules were assumed to form highly mobile species leading to the enhancement of controlling the perovskite lattice growth. Merging perovskite nanomaterials with peptides are expected to pave a way to the new class of materials possessing exceptional optoelectronic properties alongside self-assembly and sensing abilities. As a proof-of-concept, a cyclic(RGDFK) pentapeptide was used for PNP stabilization. However, peptides are known for their sensitivity to their environment. Therefore, peptide nucleic acid (PNA) was used for PNP stabilization as a robust artificial analogue for deoxyribonucleic acid (DNA). Here, optical properties of thymine-based PNA monomer and trimer stabilized PNP were studied. Additionally, the sensing ability of the PNA ligand for adenine moiety was demonstrated by photoluminescence quenching via charge transfer. We envision that combining the unique tailored structure of PNA and the prospective optical features of PNP could expand the applications especially in the field of optical sensing devices.

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