Organic Light Emitting Diodes Based on Functionalized Oligothiophenes for Display and Lighting Applications

Mazzeo, Marco; Mariano, Fabrizio; Gigli, Giuseppe; Barbarell, Giovanna

doi:10.5772/46949

Cited by 4 publications

(3 citation statements)

References 47 publications

(86 reference statements)

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“…Multifunctionality, chemical robustness, and versatility of chemical systems are some of the fundamental requirements in nanoscience and nanotechnology. Oligothiophenes fit the bill and have been used for a number of high-tech applications, including organic light-emitting diode (OLED), organic field-effect transistor (OFET), light-emitting transistors (LET), lasers, biosensors, chemosensors, and electrochromic devices. − The photophysics of oligothiophenes is characterized by high absorbance, bright fluorescence, and high chemical and optical stability. Their fluorescence can be modulated by exploiting any of the numerous and well-established synthetic protocols that can change the number of thiophene rings and the nature of side-chains attached to them .…”

Section: Introductionmentioning

confidence: 99%

Human Serum Albumin–Oligothiophene Bioconjugate: A Phototheranostic Platform for Localized Killing of Cancer Cells by Precise Light Activation

Cantelli

Malferrari

Soldà

et al. 2021

JACS Au

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The electronic, optical, and redox properties of thiophene-based materials have made them pivotal in nanoscience and nanotechnology. However, the exploitation of oligothiophenes in photodynamic therapy is hindered by their intrinsic hydrophobicity that lowers their biocompatibility and availability in water environments. Here, we developed human serum albumin (HSA)–oligothiophene bioconjugates that afford the use of insoluble oligothiophenes in physiological environments. UV–vis and electrophoresis proved the conjugation of the oligothiophene sensitizers to the protein. The bioconjugate is water-soluble and biocompatible, does not have any “dark toxicity”, and preserves HSA in the physiological monomeric form, as confirmed by dynamic light scattering and circular dichroism measurements. In contrast, upon irradiation with ultralow light doses, the bioconjugate efficiently produces reactive oxygen species (ROS) and leads to the complete eradication of cancer cells. Real-time monitoring of the photokilling activity of the HSA–oligothiophene bioconjugate shows that living cells “explode” upon irradiation. Photodependent and dose-dependent apoptosis is one of the primary mechanisms of cell death activated by bioconjugate irradiation. The bioconjugate is a novel theranostic platform able to generate ROS intracellularly and provide imaging through the fluorescence of the oligothiophene. It is also a real-time self-reporting system able to monitor the apoptotic process. The induced phototoxicity is strongly confined to the irradiated region, showing localized killing of cancer cells by precise light activation of the bioconjugate.

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Section: Introductionmentioning

confidence: 99%

Human Serum Albumin–Oligothiophene Bioconjugate: A Phototheranostic Platform for Localized Killing of Cancer Cells by Precise Light Activation

Cantelli

Malferrari

Soldà

et al. 2021

JACS Au

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“…Moreover, oligomers are prone to form ordered supramolecular structures and this has recently shown to have significant repercussions on the performance of the final device. [5,6] In particular, small conjugated molecules such as oligothiophenes (OTs), beyond retaining some of the typical molecular characteristics of their homologous with higher molecular weight, have proved to be good materials for OSCs, [7] OLEDs [8] and OFETs. [9][10][11] The optoelectronic properties of oligothiophenes and, generally, of aromatic π-conjugated systems, are largely a result of the degree of conjugation.…”

Section: Introductionmentioning

confidence: 99%

Optoelectronic Properties of A‐π‐D‐π‐A Thiophene‐Based Materials with a Dithienosilole Core: An Experimental and Theoretical Study

et al. 2019

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Two A‐π‐D‐π‐A thiophene‐based small molecules with a central dithienosilole core and dicyanovinyl (DCV) end groups were synthesized. These compounds differ only by the presence of alkyl and alkylsulfanyl chains, respectively, on the thiophene beta positions. Computational data together with the spectroscopic and electrochemical findings (obtained by means of absorption, steady‐state/time‐resolved emission techniques, and cyclic voltammetry) revealed that both molecules possess low electronic and optical band gaps, broad absorption spectra, and good stability both in p and n‐doping states, which make them suitable for optoelectronic applications. In both compounds, the HOMO–LUMO transition involves an intramolecular charge transfer from the electron‐donor dithienosilole unit to the two terminal electron‐acceptor DCV groups. A marked positive emission solvatochromism was observed for both molecules and was interpreted on the basis of the symmetry breaking in the S1 excited state. The two synthesized compounds were also compared to their shorter precursors and to similar oligothiophenes to understand how the nature of the building block influences the characteristics of the final materials. Furthermore, it was possible to better understand the contribution of the sulfur atom in modulating the optical properties of the small molecules studied.

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“…Impressive scientific and technological advances have been achieved in the field of organic light emitting diodes in the last two decades. Fundamental research to gain better understanding of the behaviour of charge carriers in organic semiconductors, for example, injection from electrodes, transport and radiative recombination have also been motivated by prospects to improve device performance [38][39][40][41][42][43][44][45][46][47][48][49][50].…”

Section: Introductionmentioning

confidence: 99%

Organic Light - Emitting Diodes and their Applications

Chandra¹,

Chandra

Jha

2014

DDF

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Organic light emitting diodes (OLEDs) have been the focus of intense study since the late 1980s, when the low voltage organic electroluminescence in small organic molecules such as Alq3, and large organic molecules such as polymers (PPV), was reported. Since that time, research has continued to demonstrate the potential of OLEDs as viable systems for displays and eco-friendly lighting applications. OLEDs offer full colour display, reduced manufacturing cost, larger viewing angle, more flexible, lower power consumption, better contrast, slimmer, etc. which help in replacing the other technologies such as LCD. The operation of OLEDs involves injection of charge carriers into organic semiconducting layers, recombination of charge carriers, formation of singlet and triplet excitons, and emission of light during decay of excitons. The maximum internal quantum efficiency of fluorescent OLEDs consisting of the emissive layer of fluorescent organic material is 25% because in this case only the 25% singlet excitons can emit light. The maximum internal quantum efficiency of phosphorescent OLEDs consisting of the emissive layer of fluorescent organic material mixed with phosphorescent material of heavy metal complexes such as platinum complexes, iridium complexes, etc. is nearly 100% because in this case both the 25% singlet excitons and 75% triplet excitons emit light. Recently, a new class of OLEDs based on thermally activated delayed fluorescence (TADF) has been reported, in which the energy gap between the singlet and triplet excited states is minimized by design, thereby promoting highly efficient spin up-conversion from non-radiative triplet states to radiative singlet states while maintaining high radiative decay rates of more than 106decays per second. These molecules harness both singlet and triplet excitons for light emission through fluorescence decay channels and provides an intrinsic fluorescence efficiency in excess of 90 per cent and a very high external electroluminescence efficiency of more than 19 per cent, which is comparable to that achieved in high-efficiency phosphorescence-based OLEDs.The OLED technology can be used to make screens large enough for laptop, cell phones, desktop computers, televisions, etc. OLED materials could someday be applied to plastic and other materials to create wall-size video panels, roll-up screens for laptops, automotive displays, and even head wearable displays. Presently, the OLEDs are opening up completely new design possibilities for lighting in the world of tomorrow whereby the offices and living rooms could be illuminated by lighting panels on the ceiling. The present paper describes the salient features of OLEDs and discusses the applications of OLEDs in displays and solid state lighting devices. Finally, the challenges in the field of OLEDs are explored. Contents of Paper

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Organic Light Emitting Diodes Based on Functionalized Oligothiophenes for Display and Lighting Applications

Cited by 4 publications

References 47 publications

Human Serum Albumin–Oligothiophene Bioconjugate: A Phototheranostic Platform for Localized Killing of Cancer Cells by Precise Light Activation

Human Serum Albumin–Oligothiophene Bioconjugate: A Phototheranostic Platform for Localized Killing of Cancer Cells by Precise Light Activation

Optoelectronic Properties of A‐π‐D‐π‐A Thiophene‐Based Materials with a Dithienosilole Core: An Experimental and Theoretical Study

Organic Light - Emitting Diodes and their Applications

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