Abstract
We present an electron spin resonance (ESR) study of Cs2CO3 and LiF doped tris(8-hydroxyquinoline) aluminum (Alq3) thin films. The g values of the Cs2CO3 and LiF doped Alq3 thin films were obtained as 2.0040 and 2.0028, repectively. The g value of the LiF doped film was very close to a theoretically calculated one for an isolated Alq3 radical anion, while Cs2CO3 doped film showed a large g shift. This feature can be explained by large spin-orbit interaction caused by heavy Cs atoms. While doping of Cs2CO3 did not showed cathode-metal (Al and Au) dependence, LiF doping required Al as cathode.
Acknowledgments
This work was partly supported by a Grant-in-Aid for Scientific Research (24560004) from JSPS and by JST, PRESTO.