Influence of thickness and annealing temperature of Polyethyleneimine ethoxylated on the luminous efficacy of Organic Light Emitting Diodes

Abstract

Organic Light Emitting Diodes (OLED) with high luminous efficacy are one of the research topics that attract a lot of attention recently. To enhance luminous efficacy researchers have employed innumerable methods, materials and technologies. Amongst many materials available, polyethyleneimine ethoxylated (PEIE) as electron injection layer shows a promise as it is stable in ambient conditions and reduces the work-function of the contact electrode and lowers the injection current. However, the insulating nature of the PEIE prevails at the higher thickness and this reduces luminous efficacy. In the present work, the effect of various thickness of the PEIE layer at different annealing temperatures on the luminous efficacy is meticulously investigated.