Electrical and optical simulations of a polymer-based phosphorescent organic light-emitting diode with high efficiency

被引:12
作者
Al-Sa'di, Mahmoud [1 ]
Jaiser, Frank [1 ]
Bagnich, Sergey [1 ]
Unger, Thomas [1 ]
Blakesley, James [1 ]
Wilke, Andreas [2 ]
Neher, Dieter [1 ]
机构
[1] Univ Potsdam, Inst Phys & Astron, D-14476 Potsdam, Germany
[2] Humboldt Univ, Inst Phys, D-12489 Berlin, Germany
关键词
conjugated polymers; high performance polymers; organic electronics; organic light-emitting diode; simulations; TCAD; ELECTROPHOSPHORESCENT DEVICES; CHARGE-TRANSPORT; EMISSION; INTERFACE; LAYER; RECOMBINATION; PERFORMANCE; COMPLEXES; INJECTION; DIPOLES;
D O I
10.1002/polb.23158
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
A comprehensive numerical device simulation of the electrical and optical characteristics accompanied with experimental measurements of a new highly efficient system for polymer-based light-emitting diodes doped with phosphorescent dyes is presented. The system under investigation comprises an electron transporter attached to a polymer backbone blended with an electronically inert small molecule and an iridium-based green phosphorescent dye which serves as both emitter and hole transporter. The device simulation combines an electrical and an optical model. Based on the known highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of all components as well as the measured electrical and optical characteristics of the devices, we model the emissive layer as an effective medium using the dye's HOMO as hole transport level and the polymer LUMO as electron transport level. By fine-tuning the injection barriers at the electron and hole-injecting contact, respectively, in simulated devices, unipolar device characteristics were fitted to the experimental data. Simulations using the so-obtained set of parameters yielded very good agreement to the measured currentvoltage, luminancevoltage characteristics, and the emission profile of entire bipolar light-emitting diodes, without additional fitting parameters. The simulation was used to gain insight into the physical processes and the mechanisms governing the efficiency of the organic light-emitting diode, including the position and extent of the recombination zone, carrier concentration profiles, and field distribution inside the device. The simulations show that the device is severely limited by hole injection, and that a reduction of the hole-injection barrier would improve the device efficiency by almost 50%. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
引用
收藏
页码:1567 / 1576
页数:10
相关论文
共 43 条
[1]   Highly efficient single-layer dendrimer light-emitting diodes with balanced charge transport [J].
Anthopoulos, TD ;
Markham, JPJ ;
Namdas, EB ;
Samuel, IDW ;
Lo, SC ;
Burn, PL .
APPLIED PHYSICS LETTERS, 2003, 82 (26) :4824-4826
[2]   Efficient green electrophosphorescence based on ambipolar nonconjugated polymers: Evaluation of transport and emission properties [J].
Bagnich, S. A. ;
Unger, Th. ;
Jaiser, F. ;
Neher, D. ;
Thesen, M. W. ;
Krueger, H. .
JOURNAL OF APPLIED PHYSICS, 2011, 110 (03)
[3]   Sensing electron transport in a blue-emitting copolymer by transient electroluminescence [J].
Bange, Sebastian ;
Kuksov, Andriy ;
Neher, Dieter .
APPLIED PHYSICS LETTERS, 2007, 91 (14)
[4]   CHARGE TRANSPORT IN DISORDERED ORGANIC PHOTOCONDUCTORS - A MONTE-CARLO SIMULATION STUDY [J].
BASSLER, H .
PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1993, 175 (01) :15-56
[5]   Method of source terms for dipole emission modification in modes of arbitrary planar structures [J].
Benisty, H ;
Stanley, R ;
Mayer, M .
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION, 1998, 15 (05) :1192-1201
[6]   Temperature dependent electron-hole recombination in polymer light-emitting diodes [J].
Blom, PWM ;
deJong, MJM ;
Breedijk, S .
APPLIED PHYSICS LETTERS, 1997, 71 (07) :930-932
[7]   Interface modification to improve hole-injection properties in organic electronic devices [J].
Choulis, SA ;
Choong, VE ;
Patwardhan, A ;
Mathai, MK ;
So, F .
ADVANCED FUNCTIONAL MATERIALS, 2006, 16 (08) :1075-1080
[8]   The effect of interfacial layer on the performance of organic light-emitting diodes [J].
Choulis, SA ;
Choong, VE ;
Mathai, MK ;
So, F .
APPLIED PHYSICS LETTERS, 2005, 87 (11)
[9]  
Flammich M., 2011, THESIS FRIEDRICH SCH
[10]  
Gong X, 2002, ADV MATER, V14, P581, DOI 10.1002/1521-4095(20020418)14:8<581::AID-ADMA581>3.0.CO