Jianhua Zou

Highly efficient polymer white-light-emitting devices with a single emission layer containing a sky–blue triplet emitter and some home-made yellow phosphorescent iridium complexes doped into a polymer host are fabricated. The optimized devices present CIE coordinates of (0.395,0.452) at a current density of 12 mA cm−2. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Inkjet printing has been considered an available way to achieve large size full-color RGB quantum dots LED display, and the key point is to obtain printed film with uniform and flat surface profile. In this work, mixed solvent of 20 vol % 1,2-dichlorobenzene (oDCB) with cyclohexylbenzene (CHB) was used to dissolve green quantum dots (QDs) with CdSe@ZnS/ZnS core/shell structure. Then, by inkjet printing, a flat dotlike QDs film without the coffee ring was successfully obtained on polyetherimide (PEI)-modified ZnO layer, and the printed dots array exhibited great stability and repeatability. Here, adding oDCB into CHB solutions was used to reduce surface tension, and employing ZnO nanoparticle layer with PEI-modified was used to increase the surface free energy. As a result, a small contact angle is formed, which leads to the enhancement of evaporation rate, and then the coffee ring effect was suppressed. The printed dots with flat surface profile were eventually realized. Moreover, inverted green QD-LEDs with PEI-modified ZnO film as electron transport layer (ETL) and printed green QDs film as emission layer were successfully fabricated. The QD-LEDs exhibited the maximum luminance of 12 000 cd/m2 and the peak current efficiency of 4.5 cd/A at luminance of 1500 cd/m2.

White polymer light-emitting devices with a peak forward-viewing power efficiency close to 40 lm W−1, corresponding to an external quantum efficiency of 28.8% and a luminous efficiency of 60 cd A−1, are demonstrated. The devices are based on two newly synthesized yellow-emitting iridium complexes functionalized with the sterically hindered diarylfluorene chromophores and are fabricated by a simple solution-processing method.

The aggregation‐induced emission (AIE) phenomenon is important in organic light‐emitting diodes (OLEDs), for it can potentially solve the aggregation‐caused quenching problem. However, the performance of AIE fluorophor‐based OLEDs (AIE OLEDs) is unsatisfactory, particularly for deep‐blue devices (CIEy < 0.15). Here, by enhancing the device engineering, a deep‐blue AIE OLED exhibits low voltage (i.e., 2.75 V at 1 cd m −2 ), high luminance (17 721 cd m −2 ), high efficiency (4.3 lm W −1 ), and low efficiency roll‐off (3.6 lm W −1 at 1000 cd m −2 ), which is the best deep‐blue AIE OLED. Then, blue AIE fluorophors, for the first time, have been demonstrated to achieve high‐performance hybrid white OLEDs (WOLEDs). The two‐color WOLEDs exhibit i) stable colors and the highest efficiency among pure‐white hybrid WOLEDs (32.0 lm W −1 ); ii) stable colors, high efficiency, and very low efficiency roll‐off; or iii) unprecedented efficiencies at high luminances (i.e., 70.2 cd A −1 , 43.4 lm W −1 at 10 000 cd m −2 ). Moreover, a three‐color WOLED exhibits wide correlated color temperatures (10 690–2328 K), which is the first hybrid WOLED showing sunlight‐style emission. These findings will open a novel concept that blue AIE fluorophors are promising candidates to develop high‐performance hybrid WOLEDs, which have a bright prospect for the future displays and lightings.

Abstract Blue organic luminescent materials play a crucial role in full‐color display and white lighting but efficient ones meeting commercial demands are very rare. Herein, the design and synthesis of tailor‐made bipolar blue luminogens with an anthracene core and various functional groups are reported. The thermal stabilities, photophysical properties, electronic structures, electrochemical behaviors, carrier transport abilities, and electroluminescence performances are systematically investigated. The luminogen TPE‐TAPBI containing a tetraphenylethene moiety shows aggregation‐induced emission, while another luminogen TriPE‐TAPBI bearing a triphenylethene unit exhibits light aggregation‐caused quenching. In comparison with TriPE‐TAPBI, TPE‐TAPBI has stronger blue emission in neat film and functions more efficiently in nondoped organic light‐emitting diodes (OLEDs). High maxima current, power, and external quantum efficiencies of 7.21 cd A −1 , 6.78 lm W −1 , and 5.73%, respectively, are attained by the nondoped blue OLED of TPE‐TAPBI (CIE x , y = 0.15, 0.16). Moreover, efficient two‐color hybrid warm white OLEDs (CIE x , y = 0.457, 0.470) are achieved using TPE‐TAPBI neat film as the blue‐emitting component, which provide total current, power, external quantum efficiencies of up to 70.5 lm W −1 , 76.0 cd A −1 , and 28% at 1000 cd m −2 , respectively. These blue and white OLEDs are among the most efficient devices with similar colors in the literature.