A5080363153- Organic Light-Emitting Diodes Research
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Semiconductor materials and devices
- Perovskite Materials and Applications
- Luminescence Properties of Advanced Materials
- Dielectric materials and actuators
- Catalytic Cross-Coupling Reactions
- Conducting polymers and applications
- Porphyrin and Phthalocyanine Chemistry
- Advanced Sensor and Energy Harvesting Materials
- Photochemistry and Electron Transfer Studies
- Nanoplatforms for cancer theranostics
- Catalytic Alkyne Reactions
- Synthesis and properties of polymers
- Image and Video Quality Assessment
- Molecular Junctions and Nanostructures
Swiss Federal Laboratories for Materials Science and Technology
2021-2024
École Polytechnique Fédérale de Lausanne
2021-2024
ETH Zurich
2020
Abstract Organic upconverters made by integrating an infrared‐sensitive photodetector with a light‐emitting diode offer low‐cost route to visualize images taken in the infrared. However, making such devices sufficiently efficient is challenging. Here, upconversion are demonstrated efficiency of 13.9% for converting infrared photons (980 nm, 5 mW cm −2 ) visible (575 nm). Infrared detected photomultiplication that includes copper thiocyanate electron‐blocking/injection layer and squaraine dye...
Gold(III) complexes are emerging as promising phosphorescent emitters for high-efficiency organic light-emitting diodes (OLEDs). However, despite recent advances in the coordination and organometallic chemistry of gold, only few compounds have been successful high-performance devices. Here, we disclose synthesis a new κ3-(N^C^C)-aminophenylalkynyl-N,N′-bisfluorenyl-Au(III) complex which exhibits current efficiency (ηCE) 56.4 cd A–1 an external quantum (ηext) 16.2% solution processable OLED...
Abstract Stretchable alternating current electroluminescent (ACEL) devices have a bright future in wearable electronics and soft robotics. Still, their market application is hindered by high operating voltages. The voltage can be reduced increasing the relative permittivity of dielectric elastomer emissive layer. Here, fluorine‐free high‐permittivity silicone functionalized with cyanopropyl side groups, specially designed for stretchable ACEL devices, introduced. polar exhibits excellent...
Abstract Organic upconversion devices (OUCs) consist of an organic infrared photodetector and visible light‐emitting diode (OLED), connected in series. OUCs convert photons from the to are use applications such as process control or imaging. Many require a fast OUC response speed, namely ability accurately detect rapidly changing signal. Here, high image‐contrast, narrowband reported that near‐infrared (NIR) light at 980 976 nm with full‐width half maximum 130 into light. Transient...
Shortwave infrared (SWIR) optical sensing and imaging are essential to an increasing number of next-generation applications in communications, process control or medical imaging. An all-organic SWIR upconversion device (OUC) consists organic sensitive photodetector (PD) light-emitting diode (OLED), connected series. OUCs directly convert visible photons, which potentially provides a low-cost alternative the current inorganic compound-based technology. For OUC applications, only few materials...
Abstract Sensitive detection of shortwave infrared (SWIR) light using organic dyes will be a significant advance toward many applications in industry and research. Furthermore, from fabrication optimization view, photogeneration charges diodes consisting single dye layer highly attractive. However, SWIR are scarce photodiodes usually utilize donor–acceptor materials combination to split excitons into charges. Here, it is demonstrated that single‐component layers several squaraine operate as...
Already in 2012, Blom et al. reported (Nature Materials 11, 882) semiconductingpolymers on a general electron-trap density of ≈ 3 × 1017 cm−3, centered at an energy ≈3.6 eV below vacuum. It was suggested that traps have extrinsic origin, with the water-oxygen complex [2(H2O)-O2] as possible candidate, based its electron affinity. However, further evidence is lacking and origin universal remained elusive. Here, polymer diodes temperature-dependence reversible investigated develop under bias...
Abstract Efficient OLED devices have been fabricated using organometallic complexes of platinum group metals. Still, the high material cost and low stability represent central challenges for their application in commercial display technologies. Based on its innate stability, gold(III) are emerging as promising candidates high‐performance OLEDs. Here, a series alkynyl‐, N ‐heterocyclic carbene (NHC)‐ aryl‐gold(III) stabilized by κ 3 ‐(N^C^C) template prepared photophysical properties...
Abstract Semiconducting polymers are being studied intensively for optoelectronic device applications, including solution‐processed light‐emitting diodes (PLEDs). Charge traps in limit the charge transport and thus PLED efficiency. It is firmly established that electron hindered by presence of universal trap density, whereas hole formation governs long‐term degradation PLEDs. Here, response PLEDs to electrical driving breaks covering timescale from microseconds (a few) hours studied,...
Abstract Polymer light‐emitting electrochemical cells (PLECs) and diodes (PLEDs) receive interest for large‐area lighting signage applications. During operation of a PLEC, p–i–n junction develops where electrons holes are injected into the film transported along n ‐ p ‐doped regions to intrinsic ( i ) region, they recombine under light emission. Conceptually, this resembles PLED device architecture equipped with Ohmic charge‐injection transport layers. The similarity between ‐region PLEC...
Abstract Strongly polarized donor‐acceptor‐donor′ diketopyrrolopyrroles, differing in the type of key donor moiety, were designed and synthesized to examine how this affects non‐radiative decay. Dyes possessing less electron‐rich N ‐carbazolyl substituents are characterized by strong yellow emission from a locally excited (LE) state, whereas replacing with more ‐phenothiazinyl substituent changes relative position charge‐transfer (CT) LE states, leading weaker, reddish‐orange fluorescence....