Ultrahigh-efficiency solution-processed simplified small-molecule organic light-emitting diodes using universal host materials
نویسندگان
چکیده
Although solution processing of small-molecule organic light-emitting diodes (OLEDs) has been considered as a promising alternative to standard vacuum deposition requiring high material and processing cost, the devices have suffered from low luminous efficiency and difficulty of multilayer solution processing. Therefore, high efficiency should be achieved in simple-structured small-molecule OLEDs fabricated using a solution process. We report very efficient solution-processed simple-structured small-molecule OLEDs that use novel universal electron-transporting host materials based on tetraphenylsilane with pyridine moieties. These materials have wide band gaps, high triplet energy levels, and good solution processabilities; they provide balanced charge transport in a mixed-host emitting layer. Orange-red (~97.5 cd/A, ~35.5% photons per electron), green (~101.5 cd/A, ~29.0% photons per electron), and white (~74.2 cd/A, ~28.5% photons per electron) phosphorescent OLEDs exhibited the highest recorded electroluminescent efficiencies of solution-processed OLEDs reported to date. We also demonstrate a solution-processed flexible solid-state lighting device as a potential application of our devices.
منابع مشابه
High-Efficiency, Solution-Processed, Multilayer Phosphorescent Organic Light-Emitting Diodes with a Copper Thiocyanate Hole-Injection/Hole-Transport Layer
Copper thiocyanate (CuSCN) is introduced as a hole-injection/hole-transport layer (HIL/HTL) for solution-processed organic light-emitting diodes (OLEDs). The OLED devices reported here with CuSCN as HIL/HTL perform significantly better than equivalent devices fabricated with a PEDOT:PSS HIL/HTL, and solution-processed, phosphorescent, small-molecule, green OLEDs with maximum luminance ≥10 000 c...
متن کاملElectroplex as a New Concept of Universal Host for Improved Efficiency and Lifetime in Red, Yellow, Green, and Blue Phosphorescent Organic Light‐Emitting Diodes
A new concept of host, electroplex host, is developed for high efficiency and long lifetime phosphorescent organic light-emitting diodes by mixing two host materials generating an electroplex under an electric field. A carbazole-type host and a triazine-type host are selected as the host materials to form the electroplex host. The electroplex host is found to induce light emission through an en...
متن کاملRed Phosphorescent Organic Light-Emitting Diodes Using Mixture System of Small-Molecule and Polymer Host
We study two types of polymer materials, poly(n-vinylcarbazole) (PVK) and starburst small-molecule 1,3,5-tris[4(diphenylamino)phenyl]benzene (TDAPB), as the host for electrophosphorescent organic light-emitting diodes (PHOLEDs) doped with red-emitting phosphor tris(1-phenylisoquinoline) iridium (III) [Ir(piq)3]. PHOLEDs employed a PVK and TDAPB blend as the host exhibited a maximum red light em...
متن کاملMulifunctional Dendritic Emitter: Aggregation-Induced Emission Enhanced, Thermally Activated Delayed Fluorescent Material for Solution-Processed Multilayered Organic Light-Emitting Diodes
Thermally activated delayed fluorescence (TADF) materials emerged as promising light sources in third generation organic light-emitting diodes (OLED). Much effort has been invested for the development of small molecular TADF materials and vacuum process-based efficient TADF-OLEDs. In contrast, a limited number of solution processable high-molecular weight TADF materials toward low cost, large a...
متن کاملA Solution Processed Flexible Nanocomposite Electrode with Efficient Light Extraction for Organic Light Emitting Diodes
Highly efficient organic light emitting diodes (OLEDs) based on multiple layers of vapor evaporated small molecules, indium tin oxide transparent electrode, and glass substrate have been extensively investigated and are being commercialized. The light extraction from the exciton radiative decay is limited to less than 30% due to plasmonic quenching on the metallic cathode and the waveguide in t...
متن کامل