Highly efficient solution-processed small-molecule white organic light-emitting diodes

Design Simulation and Preparation of White OLED Microdisplay Based on Microcavity Structure Optimization

“…Highly efficient nondoped tandem phosphorescent organic light-emitting devices (PhOLEDs) have been demonstrated by employing LiF/AL/1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN) as a charge generation unit (CGU) and ultrathin phosphorescent dyes as emitting layers (EMLs), with the maximum current efficiency of 94.9 cd/A and maximum external quantum efficiency of 31.6% [17]. Solution-processed small-molecule white organic light-emitting diodes were fabricated with a cohost of hole transporter (TCTA) and electron transporter (SPPO13), with the maximum efficiencies of 40.9 cd/A at the practical luminance of 1000 cd/m 2 [18]. e acquisition of white OLED devices was mostly achieved by doping and mixing a variety of colors.…”

Color-Stable White Organic Light-Emitting Diodes Utilizing a Blue-Emitting Electron-Transport Layer

“…White organic light-emitting diodes (WOLEDs) are of great interest in solid-state lighting and other applications. − A variety of approaches have been proposed for the realization of white emission. On the basis of the device-processing methods, WOLEDs can be divided into small-molecule ,− ,,− and polymer-based devices. ,,,− The small-molecule devices are fabricated by thermal evaporation in which multiple layers can be deposited in a one-run, whereas the later polymer-based devices can be processed by spin-casting, screen printing, or inkjet printing techniques.…”

“…White organic light-emitting diodes (WOLEDs) are of great interest in solid-state lighting and other applications. − A variety of approaches have been proposed for the realization of white emission. On the basis of the device-processing methods, WOLEDs can be divided into small-molecule ,− ,,− and polymer-based devices. ,,,− The small-molecule devices are fabricated by thermal evaporation in which multiple layers can be deposited in a one-run, whereas the later polymer-based devices can be processed by spin-casting, screen printing, or inkjet printing techniques. The greatest advantage of the later approach is that it can significantly reduce the cost in mass production especially for large-area displays.…”

“…The greatest advantage of the later approach is that it can significantly reduce the cost in mass production especially for large-area displays. The performance of both small-molecule ,, and polymer ,− WOLEDs has been greatly enhanced by the use of phosphorescent compounds as the emitters because both singlet and triplet excited states can be utilized. For small-molecule WOLEDs, the phosphors were doped into the host by coevaporation and the white light was realized by several active layers with each layer emitting a primary color ,, or from a triple-doped emissive layer. , This method of coevaporation is complicated and expensive because very precise control of the ratios of the red-, green-, and blue-emitting dopants is needed to obtain white emission.…”

Enhanced near-infrared electroluminescence from a neodymium complex in organic light-emitting diodes with a solution-processed exciplex host

“…12 SPPO13 and TCTA are employed for their high charge carrier mobility and solubility in common organic solvents that enables fabrication of highquality thin films. [13][14][15] The EML was deposited on top of the PEDOT:PSS layer, according to the procedure by Chen et al 13 Atomic force microscope (AFM) images of SPPO13:TCTA and SPPO13:TCTA:Nd(TTA)3Phen films prepared by spin-coating on quartz substrates are shown in Fig. S2 in the supplementary material.…”