Abstract
The electroluminescence efficiency of Ir-based green emitter devices is very sensitive to the nature of the hole transport layer used. We show that by inserting a 1 nm layer of bis[4-(N,N-diethylamino)-2-methylphenyl](4- methylphenyl)methane (MPMP) in a 4, 4′ - bis- (carbazol-9-yl) biphenyl (CBP) hole transport layer, a device that combines the positive attributes of both MPMP (high efficiency) and CBP (low injection voltage) is obtained. These results can be understood based on a combined ultraviolet photoemission spectroscopy/inverse photoemission spectroscopy study, which reveals the very low electron affinity and superior electron blocking capability of MPMP.
Original language | English (US) |
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Article number | 193501 |
Pages (from-to) | 1-3 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 87 |
Issue number | 19 |
DOIs | |
State | Published - Nov 7 2005 |
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)