Finite element analysis on the electrical and optical properties in HTL/mCP/ETL multilayer organic light emitting diode device structure.

In this paper, we report our numerical study on the electrical and optical properties in HTL/mCP/ETL multilayer organic light emitting diode (OLED) device structure. Our finite element method (FEM) model includes the transport behavior of electrons and holes, the generation and decay of excitons, and emission and extinction properties of excitons. We employ the multilayer structure which consists of 1,1-bis[(di-4-tolylamino)phenyl] cyclohexane (TAPC); 4,4'-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD); 4,4'-bis[N-(p-tolyl)-N-phenylamino] biphenyl (TPD); 3,5'-N,N'-dicarbazole-benzene (mCP); 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP); 4,7-diphenyl-1, 10-phenanthroline (BPhen). We report our observation of the effect of the different hole transport layer following TAPC, α-NPD, TPD and also discuss the effect of different electron transport layer following BCP, BPhen. Our simulation revealed that the charge balance results in a significant effect on the recombination density which is related to the generation of excitons.