Enhanced Brightness and Efficiency in Organic Light-Emitting Devices Using an LiF-Doped Electron-injecting Layer with Aluminium Cathode

Organic light-emitting devices(OLEDs)with enhanced brightness and efficiency were developed using an LiF-doped organic layer as an electron-injecting layer besides the aluminium cathode.The typical device structure is glass substrate/indium-tin-oxide/N,N'-bis(3-methyphenyl)-N,N'-diphenylbenzidize/8-tris-hydroxyquinoline aluminium(Alq3)/LiF-doped Alq3/Al.An optimized device with an LiF-doped Alq3 layer showed brightness over 15300 cd/m^(2),while the device without the LiF-doped Alq3 layer exhibited only 3200 cd/m^(2),also,the luminance efficiency of the former was 4-5 times as that of the latter.This is another way to improve the OLEDs performance,especially in applications of OLEDs with a large active area.