Tuning hole-injection with self-assembled layer on silver electrode for top-emitting OLED applications

摘要

A series of n-alkanethiol, cyano-terminated n-alkanethiol, and fluorine-substituted benzyl mercaptans were used to modify the silver anode in the fabrication of top-emitting electroluminescent devices. The efficiency of charge injection and device performance were investigated. The study shows that the size/direction of the dipole associated with the monolayer-forming molecule serves to modulate the metal work function and the charge injection barrier, whereas the alkyl chain length allows a fine-tuning of charge balance in the recombination zone. A high current efficiency of ～10.2 cd/A and a luminescence of ～10800 cd/m~2 at 200 Ma were achieved with the NC-C_(11)SH-modified devices.