Polymer light-emitting diodes with a phenyleneethynylene derivative as a novel hole blocking layer for efficiency enhancements

Guillaume Wantz (1, 2) , Olivier J. Dautel (3, 4) , Laurence Vignau (1, 2) , Françoise Serein-Spirau (3, 4) , Jean-Pierre Lère-Porte (3, 4) , Lionel Hirsch (1, 5) , Joël J.E. Moreau (3, 4) , Jean-Paul Parneix (1, 2)

1 IMS - Laboratoire de l'intégration, du matériau au système
2 LPIOM - Laboratoire de physique des interactions ondes matières
3 ICGM ICMMM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
4 HMM - Hétérochimie moléculaire et macromoléculaire
5 IXL - Laboratoire d'études de l'intégration des composants et systèmes électroniques

This paper reports on the use of an electron transport layer (ETL) in polymer light-emitting diodes based on poly(2,5-bis(3',7'-dimethyl-octyloxy)l,4-phenylene-vinylene) (BDMO-PPV). This ETL is inserted between BDMO-PPV and a calcium cathode as a hole blocking layer (HBL). A novel phenyleneethynylene derivative (ImPE) is proposed and compared to well-known materials such as tris(8-hydroxyquinoline) aluminum (Alq[3]) and bathocuproine (BCP). Efficient hole blocking is achieved leading to yield improvements at low luminances. With a 8 nm-thick ImPE layer, at 1 cd/m[2], the power efficiency reaches 1.2 lm/W whereas a BDMO-PPV-only PLED exhibits a 0.13 lm/W power efficiency. ImPE enables to reach higher performances than Alq[3] for low luminances (<20 cd/m[2]). However, for luminances higher than 350 cd/m[2], it is demonstrated that the hole blocking in no more efficient because of a too strong electric field.

Domaines: Chimie organique; Chimie théorique et/ou physique

Guillaume Wantz, Olivier J. Dautel, Laurence Vignau, Françoise Serein-Spirau, Jean-Pierre Lère-Porte, et al.. Polymer light-emitting diodes with a phenyleneethynylene derivative as a novel hole blocking layer for efficiency enhancements. Synthetic Metals, 2006, 156 (9-10), pp.690-694. ⟨10.1016/j.synthmet.2006.03.007⟩. ⟨hal-00163119⟩