1422951-99-2Relevant academic research and scientific papers
Crosslinkable TAPC-based hole-transport materials for solution-processed organic light-emitting diodes with reduced efficiency roll-off
Liaptsis, Georgios,Meerholz, Klaus
, p. 359 - 365 (2013/03/14)
1-Bis[4-[N,N-di(4-tolyl)amino]phenyl]-cyclohexane (TAPC) has been widely used in xerography and organic light-emitting diodes (OLEDs), but derivatives are little known. Here, a new series of solution-processable, crosslinkable hole conductors based on TAPC with varying highest occupied molecular orbital (HOMO) energies from -5.23 eV to -5.69 eV is implemented in blue phosphorescent OLEDs. Their superior perfomance compared with the well-known N4,N4,N4′, N4′-tetraphenylbiphenyl-4,4′-diamine (TPDs) analogues regarding hole-injection and mobility, electron and exciton blocking capabilities, efficiency, and efficiency roll-off is demonstrated. Overall, the TAPC-based devices feature higher luminous and power efficiency over a broader range of brightness levels and reduced efficiency roll off. A systematic broadening of the emission zone is observed as the hole-injection barrier between the anode and the hole-transporting layer increased. The influence of varying hole-injection and electron-blocking properties is studied using different crosslinkable hole conductors of the 4,4′-(cyclohexane-1,1-diyl)bis(N,N- dip-tolylaniline) (TAPC) family in blue phosphorescent organic light-emitting diodes (OLEDs) consisting of polyvinylcarbazole (PVK)/bis[(4,6-difluorophenyl) pyridinato-N,C2](picolinato)iridium(III) (FIrpic)/1,3-bis(5-(4-tert- butylphenyl)-1,3,4-oxadiazol-2-yl)benzene (OXD-7)-based solution-processed devices. Copyright
