Heterojunction effect on the charge injection and transport

✍ Scribed by ShanYu Quan; Linmei Yang; Feng Teng; Zheng Xu; Yongsheng Wang

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 239 KB
• Volume: 405
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2009.09.001

✦ Synopsis

The charge injection and transport across an organic heteroinjection of is investigated. The heteroinjection is formed by a poly-p-phenylene vinylene derivative (MEH-PPV) hole injection layer with a poly(9,9-dioctylfluorene) (PFO) hole accepting layer on top. The electric field in the accepting layer is obtained after correcting the applied voltage for the voltage drop across the injecting layer due to the buildup of space charge. The distribution of electric field in the accepting layer has effect on the transport of charge. At high electric fields, the current across the heterojunction exhibits only a weak dependence on the field. The strong dependence at low fields can be explained by taking the increase of the Fermi level into account, which effectively modifies the barrier for charge carriers waiting for a jump across the heterojunction.