Hole-transporting side-chain polystyrenes based on TCTA with tuned glass transition and optimized electronic properties. Issue 101 (30th September 2015)

• Record Type: Journal Article
• Authors: Limberg, Felix R. P.; Miasojedovas, Arunas; Pingel, Patrick; Reisbeck, Felix; Janietz, Silvia; Monkman, Andrew P.; Krüger, Hartmut
• Is Part Of: RSC advances. Volume 5:Issue 101(2015)
• Page Start: 83122
• Page End: 83128
• Publication Date: 2015-09-30
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra12963j
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The development of crosslinkable materials for solution processable OLEDs presents challenges, especially regarding the adjustment of the glass transition, which has a significant influence on crosslinking kinetics and device life-time. Abstract : The development of crosslinkable materials for the fabrication of solution processable OLEDs presents challenges, especially regarding the adjustment of the glass transition ( T g ), which has a significant influence on crosslinking kinetics and device life-time. Crosslinkable hole transport materials based on poly( N, N -bis(4-(9 H -carbazol-9-yl)phenyl)-4-vinylaniline) (poly-TCTA) with covalently attached plasticizers for T g control and azide functionalities for azide-alkyne crosslinking are presented. These polymers have an optimal T g of around 150 °C and show superior crosslinking performances and solution resistibilities. Incorporation of electron-pushing alkoxides to the pendant groups combines the T g adjustment approach with a systematic tuning of the HOMO level from −5.7 to −5.3 eV. All presented polymers have good charge transport and injection properties and are ideal for applications in phosphorescent OLEDs due to their high triplet energies (>2.8 eV). The new crosslinkable poly-TCTA-based materials are applied as hole-transport layers (HTLs) in fully solution-processed OLEDs. An improvement of the device performance is demonstrated for OLEDs with additional crosslinked HTL.