caa a22 4500 445371161 CHVBK 20180317142947.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s00340-011-4703-0 doi (NATIONALLICENCE)springer-10.1007/s00340-011-4703-0 Highly efficient bipolar connecting layers for tandem organic light-emitting devices [Elektronische Daten] [L. Niu, Y. Guan, C. Kong, Y. Cui, Y. Ren, S. Tao, J. Zhou, J. Yu] A highly efficient tandem organic light-emitting device (OLED) has been fabricated by using an effective bipolar connecting layer structure. The connecting layers were made up of a layer of magnesium (Mg): 2,7-dipyrenyl-9,9-diphenyl fluorene (N-DPF) and a layer of tungsten trioxide (WO3). Such a connecting layer structure permits efficient opposite holes and electrons flowing into two adjacent emitting units. The current efficiency of the two-unit tandem device can be dramatically enhanced by more than four times compared with that of the conventional single-unit device. At 60 mA/cm2, the current efficiency of the tandem OLED using the connecting layers of Mg: N-DPF/WO3 was about 8.15 cd/A. The results can be marked as a breakthrough approach to improve the current efficiency and brightness of OLEDs. Furthermore, a model of the carrier tunneling into light-emitting units is proposed based on carrier balance and field-assisted tunneling. It indicates that the connecting layer structure functions as the origin of high efficiency for the tandem OLEDs. Springer-Verlag, 2011 Niu L. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut Guan Y. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut Kong C. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut Cui Y. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut Ren Y. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut Tao S. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut Zhou J. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut Yu J. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut Applied Physics B Springer-Verlag 105/4(2011-12-01), 857-862 0946-2171 105:4<857 2011 105 340 https://doi.org/10.1007/s00340-011-4703-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00340-011-4703-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Niu L. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut NATIONALLICENCE 700 1- Guan Y. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut NATIONALLICENCE 700 1- Kong C. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut NATIONALLICENCE 700 1- Cui Y. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut NATIONALLICENCE 700 1- Ren Y. Key Laboratory of Optical Engineering, College of Physics and Electronic Engineering, Chongqing Normal University, 400047, Chongqing, China aut NATIONALLICENCE 700 1- Tao S. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut NATIONALLICENCE 700 1- Zhou J. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut NATIONALLICENCE 700 1- Yu J. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, 610054, Chengdu, China aut NATIONALLICENCE 773 0- Applied Physics B Springer-Verlag 105/4(2011-12-01), 857-862 0946-2171 105:4<857 2011 105 340 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer