Green to white to blue OLEDs by using PBD as a chromaticity-tuning layer [An article from: Displays]

This digital document is a journal article from Displays, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Blue to white to green light-emitting diodes with structure ITO/PVK:DPPhP(5%)/PBD(xnm)/Alq"3(5nm)/LiF(0.3nm)/Al have been obtained. DPPhP (1,3-diphenyl-5-(9-phenanthryl)-4,5-dihydro-1-H-pyrazole), which performs good blue-emitting and hole-transporting properties, is synthesized and used as dopant. When the thickness of PBD layer varies from 0 to 5 to 10nm, green to white to blue emission is achieved. Based on the energy band theory and carries tunneling theory, we consider that PBD layer plays a chromaticity-tuning role and the color-variable EL is ascribe to its modulation function on carrier recombination zone.