Abstract
We investigated the electronic structures at the interface of Al/lithium cobalt oxide (LiCoO2)/tris(8-hydoxyquinoline) aluminum (Alq 3) to elucidate the origin of the electron injection enhancement with the insertion of the LiCoO2 layer in organic light-emitting devices using in situ photoelectron spectroscopy experiments. We discovered that LiCoO2 was decomposed into lithium oxide (Li2O) by thermal evaporation, and only Li2O was deposited on the desired substrate. Li2O forms a strong interfacial dipole, which reduces the surface potential on Alq3 due to its extremely low work function. As a result, the electron injection barrier was dramatically decreased by the Li 2O layer. Furthermore, there is no strong chemical interaction at the interface of Al/Li2O/Alq3; hence, this would contribute to extend the device lifetime.
| Original language | English |
|---|---|
| Article number | 033302 |
| Journal | Applied Physics Letters |
| Volume | 102 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2013 Jan 21 |
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All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)
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Strong interfacial dipole formation with thermal evaporation of lithium cobalt oxide for efficient electron injections. / Lee, Hyunbok; Park, Soohyung; Lee, Jeihyun; Lee, Younjoo; Shin, Dongguen; Jeong, Kwangho; Yi, Yeonjin.
In: Applied Physics Letters, Vol. 102, No. 3, 033302, 21.01.2013.Research output: Contribution to journal › Article
TY - JOUR
T1 - Strong interfacial dipole formation with thermal evaporation of lithium cobalt oxide for efficient electron injections
AU - Lee, Hyunbok
AU - Park, Soohyung
AU - Lee, Jeihyun
AU - Lee, Younjoo
AU - Shin, Dongguen
AU - Jeong, Kwangho
AU - Yi, Yeonjin
PY - 2013/1/21
Y1 - 2013/1/21
N2 - We investigated the electronic structures at the interface of Al/lithium cobalt oxide (LiCoO2)/tris(8-hydoxyquinoline) aluminum (Alq 3) to elucidate the origin of the electron injection enhancement with the insertion of the LiCoO2 layer in organic light-emitting devices using in situ photoelectron spectroscopy experiments. We discovered that LiCoO2 was decomposed into lithium oxide (Li2O) by thermal evaporation, and only Li2O was deposited on the desired substrate. Li2O forms a strong interfacial dipole, which reduces the surface potential on Alq3 due to its extremely low work function. As a result, the electron injection barrier was dramatically decreased by the Li 2O layer. Furthermore, there is no strong chemical interaction at the interface of Al/Li2O/Alq3; hence, this would contribute to extend the device lifetime.
AB - We investigated the electronic structures at the interface of Al/lithium cobalt oxide (LiCoO2)/tris(8-hydoxyquinoline) aluminum (Alq 3) to elucidate the origin of the electron injection enhancement with the insertion of the LiCoO2 layer in organic light-emitting devices using in situ photoelectron spectroscopy experiments. We discovered that LiCoO2 was decomposed into lithium oxide (Li2O) by thermal evaporation, and only Li2O was deposited on the desired substrate. Li2O forms a strong interfacial dipole, which reduces the surface potential on Alq3 due to its extremely low work function. As a result, the electron injection barrier was dramatically decreased by the Li 2O layer. Furthermore, there is no strong chemical interaction at the interface of Al/Li2O/Alq3; hence, this would contribute to extend the device lifetime.
UR - http://www.scopus.com/inward/record.url?scp=84872970744&partnerID=8YFLogxK
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U2 - 10.1063/1.4789394
DO - 10.1063/1.4789394
M3 - Article
AN - SCOPUS:84872970744
VL - 102
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 3
M1 - 033302
ER -