7 research outputs found
A carbon-doped tantalum dioxyfluoride as a superior electron transport material for high performance organic optoelectronics
Carbon Nanodots as Electron Transport Materials in Organic Light Emitting Diodes and Solar Cells
Charge injection and transport interlayers play a crucial role in many classes of optoelectronics, including organic and perovskite ones. Here, we demonstrate the beneficial role of carbon nanodots, both pristine and nitrogen-functionalized, as electron transport materials in organic light emitting diodes (OLEDs) and organic solar cells (OSCs). Pristine (referred to as C-dots) and nitrogen-functionalized (referred to as NC-dots) carbon dots are systematically studied regarding their properties by using cyclic voltammetry, Fourier-transform infrared (FTIR) and UV–Vis absorption spectroscopy in order to reveal their energetic alignment and possible interaction with the organic semiconductor’s emissive layer. Atomic force microscopy unravels the ultra-thin nature of the interlayers. They are next applied as interlayers between an Al metal cathode and a conventional green-yellow copolymer—in particular, (poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo-{2,1′,3}-thiadiazole)], F8BT)—used as an emissive layer in fluorescent OLEDs. Electrical measurements indicate that both the C-dot- and NC-dot-based OLED devices present significant improvements in their current and luminescent characteristics, mainly due to a decrease in electron injection barrier. Both C-dots and NC-dots are also used as cathode interfacial layers in OSCs with an inverted architecture. An increase of nearly 10% in power conversion efficiency (PCE) for the devices using the C-dots and NC-dots compared to the reference one is achieved. The application of low-cost solution-processed materials in OLEDs and OSCs may contribute to their wide implementation in large-area applications
Functionalized Zinc Porphyrins with Various Peripheral Groups for Interfacial Electron Injection Barrier Control in Organic Light Emitting Diodes
Room-temperature deposited fluorine-doped tantalum pentoxide for stable organic solar cells
Low Work Function Lacunary Polyoxometalates as Electron Transport Interlayers for Inverted Polymer Solar Cells of Improved Efficiency and Stability
From Crossref via Jisc Publications RouterHistory: epub 2017-06-28, issued 2017-06-28, ppub 2017-07-12Funder: General Secretariat for Research and Technology; FundRef: 10.13039/501100003448Funder: European Regional Development Fund; FundRef: 10.13039/501100008530Funder: European Social Fund; FundRef: 10.13039/50110000489
Defect passivation in perovskite solar cells using an amino-functionalized BODIPY fluorophore
Triazine-Substituted Zinc Porphyrin as an Electron Transport Interfacial Material for Efficiency Enhancement and Degradation Retardation in Planar Perovskite Solar Cells
Motivated
by the excellent electron-transfer capability of porphyrin molecules
in natural photosynthesis, we introduce here the first application
of a porphyrin compound to improve the performance of planar perovskite
solar cells. The insertion of a thin layer consisting of a triazine-substituted
Zn porphyrin between the TiO<sub>2</sub> electron transport layer
and the CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> perovskite film
significantly augmented electron transfer toward TiO<sub>2</sub> while
also sufficiently improved the morphology of the perovskite film.
The devices employing porphyrin-modified TiO<sub>2</sub> exhibited
a significant increase in the short-circuit current densities and
a small increase in the fill factor. As a result, they delivered a
maximum power conversion efficiency (PCE) of 16.87% (average 14.33%),
which represents a 12% enhancement compared to 15.01% (average 12.53%)
of the reference cell. Moreover, the porphyrin-modified cells exhibited
improved hysteretic behavior and a higher stabilized power output
of 14.40% compared to 10.70% of the reference devices. Importantly,
nonencapsulated perovskite solar cells embedding a thin porphyrin
interlayer showed an elongated lifetime retaining 86% of the initial
PCE after 200 h, while the reference devices exhibited higher efficiency
loss due to faster decomposition of CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> to PbI<sub>2</sub>