Highly efficient tandem p - i - n organic light-emitting diodes adopting a low temperature evaporated rhenium oxide interconnecting layer

• Published in: Applied physics letters Vol. 93; no. 10; pp. 103304 - 103304-3
• Main Authors: Leem, Dong-Seok, Lee, Jae-Hyun, Kim, Jang-Joo, Kang, Jae-Wook
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 08-09-2008
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2979706

High quality interconnection units (ICUs) with a high transparency and superior charge gen
erating capability for tandem organic light-emitting diodes (OLEDs) are developed. The ICUs of rubidium carbonate-doped 4,7-diphenyl-1,10-phenanthroline/rhenium oxide
(
Re
O
3
)
-doped
N
,
N
′
-diphenyl-
N
,
N
′
-bis(
1
,
1
′
-biphenyl)-
4
,
4
′
-diamine layers with or without an additional
Re
O
3
interlayer produce high transmittance (88%-92% at
420
-
700
nm
) and spontaneous internal charge generation properties. A very high efficiency of
∼
129
cd
∕
A
has been demonstrated from only two stacked green
p
-
i
-
n
OLEDs by employing the developed ICUs. The relationship between the device efficiency and internal charge generation within the ICUs is further described by means of the capacitance measurements.