Influence of Disassociation Probability on External Quantum Efficiency in Organic Electrophosphorescent Devices  

作　　者：ZHANG Jian-hua OU YANG Jun LI Xue-yong LI Hong-jian 

机构地区：[1]Department of Physics, Xiangnan University, Chenzhou 423000, CHN [2]College of Physics Science and Technology, Central South University, Changsha 410083, CHN

出　　处：《Semiconductor Photonics and Technology》2007年第3期181-185,共5页半导体光子学与技术（英文版）

基　　金：Excellent Youth Foundation of Hunan Province(03JJY1008) ;Science Foundation for Post-doctorate of China(2004035083) ;National Science Foundation of Hunan Province(06JJ20034)

摘　　要：An analytical model is presented to calculate the disassociation probability and the external quantum efficiency at high field in doped organic electrophosphorescence(EPH) devices. The charge recombination process and the triplet(T)-triplet(T) annihilation processes are taken into account in this model. The influences of applied voltage and the thickness of the device on the disassociation probability, and of current density and the thickness of the device on the external quantum efficiency are studied thoroughly by including and ignoring the disassociation of excitons. It is found that the dissociation probability of excitons will come close to 1 at high electric field, and the external EPH quantum efficiency is almost the same at low electric field. There is a large discrepancy of the external EPH quantum efficiency at high electric field for including or ignoring the disassociation of excitons.An analytical model is presented to calculate the disassociation probability and the external quantum efficiency at high field in doped organic electrophosphorescence（EPH） devices. The charge recombination process and the triplet（T）-triplet（T） annihilation processes are taken into account in this model. The influences of applied voltage and the thickness of the device on the disassociation probability, and of current density and the thickness of the device on the external quantum efficiency are studied thoroughly by including and ignoring the disassociation of excitons. It is found that the dissociation probability of excitons will come close to 1 at high electric field, and the external EPH quantum efficiency is almost the same at low electric field. There is a large discrepancy of the external EPH quantum efficiency at high electric field for including or ignoring the disassociation of excitons.

关 键 词：ELECTROPHOSPHORESCENCE disassociation probability TRIPLET external quantum efficiency 

分 类 号：TN873[电子电信—信息与通信工程]