Photoconduction and Electroluminescence of Copper (II) Protoporphyrin and Chlorin Cu-C-e6

Cu (II) protoporphyrin Cu-PP-IX and chlorin Cu-C-e6 were found to have both thin solid film formation and charge carrier transport abilities. In the layers deposited by resistive thermal evaporation, the mobilities of holes and electrons are on the order of 10−5 cm2 V−1 s−1. Organic light-emitting diodes incorporating the dye molecules as emitting dopants demonstrate electroluminescence in the UV and near-IR ranges

Charge Carrier Mobility in Poly(N,N′-bis-4-butylphenyl-N,N′-bisphenyl)benzidine Composites with Electron Acceptor Molecules

Polymer composites based on poly(N,N′-bis-4-butylphenyl-N,N′-bisphenyl)benzidine (poly-TPD) with PCBM and copper(II) pyropheophorbide derivative (Cu-PP) were developed. In thin films of the poly-TPD and Cu-PP composites, the charge carrier mobility was investigated for the first time. In the ternary poly-TPD:PCBM:Cu-PP composite, the electron and hole mobilities are the most balanced compared to binary composites and the photoconductivity is enhanced due to the sensitization by Cu-PP in blue and red spectral ranges. The new composites are promising for use in the development of photodetectors

Extended UV detection bandwidth: h-BN/Al powder nanocomposites photodetectors sensitive in a middle UV region due to localized surface plasmon resonance effect

The development of high-effective photodetectors operating in a wide spectral range is an important technological task. In this work we have demonstrated that the detection bandwidth of h-BN photodetectors in the UV range can be extended due to the surface plasmon resonance (SPR) effect. Theoretical calculations showed that, among Al, Au, Ag, and Cu, Al is the most suitable metal for the h-BN UV sensible detectors due to the SPR effect in the middle UV range. Based on the theoretical predictions, a simple and highly efficient method for obtaining h-BN/Al nanocomposites for localized SPR-based UV detectors was developed. It was demonstrated that the h-BN/Al material is sensitive to UV radiation with a wavelength of 266 nm that is far away of the detection limit of 240 nm inherent for pure h-BN

New Unsymmetrically Substituted Benzothiadiazole-Based Luminophores: Synthesis, Optical, Electrochemical Studies, Charge Transport, and Electroluminescent Characteristics

Three new benzothiadiazole (BTD)-containing luminophores with different configurations of aryl linkers have been prepared via Pd-catalyzed cross-coupling Suzuki and Buchwald–Hartwig reactions. Photophysical and electroluminescent properties of the compounds were investigated to estimate their potential for optoelectronic applications. All synthesized structures have sufficiently high quantum yields in film. The BTD with aryl bridged carbazole unit demonstrated the highest electrons and holes mobility in a series. OLED with light-emitting layer (EML) based on this compound exhibited the highest brightness, as well as current and luminous efficiency. The synthesized compounds are not only luminophores with a high photoluminescence quantum yield, but also active transport centers for charge carriers in EML of OLED devices

On the efficiency limit of ZnO/CH3NH3PbI3/CuI perovskite solar cells

[eng] Organometal triiodide perovskites are promising, high-performance absorbers in solar cells. Considering the perovskite as a thin film absorber, we solve transport equations and analyse the efficiency of a simple heterojunction configuration as a function of electron-hole diffusion lengths. We found that for a thin film thickness of order 1 micron the maximum efficiency about 31% could be achieved at the diffusion length of ∼100 micron

Ultrathin Polydiacetylene-Based Synergetic Composites with Plasmon-Enhanced Photoelectric Properties

Fabricating plasmon-enhanced organic nanomaterials with technologically relevant supporting architectures on planar solids remains a challenging task in the chemistry of thin films and interfaces. In this work, we report a bottom-up assembly of ultrathin layered composites of conductive polymers with photophysical properties enhanced by gold nanoparticles. The polydiacetylene component was formed by photopolymerization of a catanionic mixture of pentacosadiynoic surfactants on a surface of citrate-stabilized gold hydrosol monitored by a fiber optic spectrometer. Microscopic examination of the 3 nm thick solid-immobilized film showed that gold nanoparticles (AuNPs) do not aggregate within the monolayer upon polymerization. This polydiacetylene/AuNPs monolayer was coupled with 60 nm thick polyaniline-based layer deposited atop. The resulting polymer composite with an integrated 4-stripe electric cell showed nonadditive electric behavior due to the formation of electron–hole pairs with increased charge carrier mobility at the interface between the polymer layers. Under visible light irradiation of the composite film, a plasmonic effect of the gold nanoparticles was observed at the onset of photoconductivity, although neither polydiacetylene nor the polyaniline component alone are photoconductive polymers. The results indicate that our bottom-up strategy can be expanded to design other plasmon-enhanced ultrathin polymer composites with potential applications in optoelectronics and photovoltaics

Pyrimidine-Based Push–Pull Systems with a New Anchoring Amide Group for Dye-Sensitized Solar Cells

New donor–π–acceptor pyrimidine-based dyes comprising an amide moiety as an anchoring group have been designed. The dyes were synthesized by sequential procedures based on the microwave-assisted Suzuki cross-coupling and bromination reactions. The influence of the dye structure and length of π-linker on the photophysical and electrochemical properties and on the photovoltaic effectiveness of dye-sensitized solar cells was investigated. An increase in efficiency with a decrease in the length of π-linker was revealed. The D1 dye with only one 2,5-thienylene-linker provided the highest power conversion efficiency among the fabricated dye sensitized solar cells