Based on the device structure of indium tin oxide (ITO)/N,N′- diphenyl-N,N′-bis(1-naphthyl-phenyl)-1,1′-biphenyl-4, 4′-diamine (NPB)/4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7- tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB)/tris (8-hydroxy quinoline) aluminum (Alq3)/NPB/bathocuproine (BCP)/Al, the variation of emissive spectra with voltage and emissive unit (DCJTB/Alq3/NPB) parameters has been investigated. All electroluminescent spectra contain two components: blue emission from NPB and red emission of DCJTB. The Alq3 emission is not observed due to its relative shallow LUMO (the lowest unoccupied molecular orbital) and deep HOMO (the highest occupied molecular orbital). The emission of NPB is increased with voltages as well as the thickness of NPB and Alq3 for more holes escape from DCJTB and get in NPB to recombine with electrons.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces, Coatings and Films