Comparison of photoexcited energy transfer in the organic double-layer and multilayer quantum well structures

Organic multiple quantum well structures (OMQWs) and double-layer structures (DLs) are prepared, which consist of alternate organic materials PBD (2-(4-biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole) and Alq3 (tris (8-hydroxyquinoline) aluminum). From the energy diagram, it is similar to type-I quantum well structure of inorganic semiconductor, in which PBD and Alq3 are both electron-transporting materials, PBD is used as a barrier layer and Alq3 as a well layer and emitter. The photoluminescence characteristics of OMQWs and DLs are investigated. The photoexcited energy transfer from PBD to Alq3 in both structures is different with different periods and different layer thicknesses.