Sistemas poliméricos semicondutores para aplicação como camada ativa em LED.

Abstract

Polymer light emiting diodes (PLEDs) were manufactured using poly(9vinylcarbazole) (PVK), poly(9,9-dioctylfluorene) (PFO) and poly(9,9-dioctylfluorenealt-1,4-fluorphenylene) (PF PF ) doped with different concentrations of tris-(2phenylpyridinate) iridium(III) [Ir(ppy) 3 ],a phosphorescent dye, as the active layer.Results showed that PFO based devices doped with 4 wt. % of Ir(ppy) 3 presented the highest current and power efficiencies, and the PVK based devices' electroluminescence spectrum showed an emission centered at 540 nm, suggesting that a charge unbalance and light emission from the injection layer of aluminum doped zinc oxide (AZO) occurred. Therefore, studies based on the PVK:AZO system and different PVK's average molar masses were elaborated to observe the PLEDs' electrical and optical properties. Results showed that AZO is a photo/electroluminescent material and it is responsible for the broad emission in the visible range. The hybrid device showed near pure white light emission and its purity reached 0.19.