TY - JOUR
T1 - Electroluminescence from completely horizontally oriented dye molecules
AU - Komino, Takeshi
AU - Sagara, Yuta
AU - Tanaka, Hiroyuki
AU - Oki, Yuji
AU - Nakamura, Nozomi
AU - Fujimoto, Hiroshi
AU - Adachi, Chihaya
N1 - Funding Information:
This work was supported in part by the Funding Program for World-Leading Innovative R&D on Science and Technology, JSPS KAKENHI Grant No. 16K17972, and the International Institute for Carbon Neutral Energy Research (WPI-I2CNER) sponsored by the Ministry of Education, Culture, Sports, Science and Technology. The authors thank Sumika Chemical Analysis Center for the TEM/EELS measurements, Ms. Kusuhara for supplying PPT, and Mr. Haraguchi for his early contribution in optimizing the device structure. T.K. thanks Kyushu University Interdisciplinary Programs in Education and Projects in Research Development and Mr. Takeshi Kaku and Mr. Akira Kawabata of the Instrumental Analysis Laboratory at Fukuoka Industry-Academia Symphonicity for the valuable discussion regarding the film density evaluation by electron microscopy
Publisher Copyright:
© 2016 Author(s).
PY - 2016/6/13
Y1 - 2016/6/13
N2 - A complete horizontal molecular orientation of a linear-shaped thermally activated delayed fluorescent guest emitter 2,6-bis(4-(10Hphenoxazin-10-yl)phenyl)benzo[1,2-d:5,4-d′] bis(oxazole) (cis-BOX2) was obtained in a glassy host matrix by vapor deposition. The orientational order of cis-BOX2 depended on the combination of deposition temperature and the type of host matrix. Complete horizontal orientation was obtained when a thin film with cis-BOX2 doped in a 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) host matrix was fabricated at 200 K. The ultimate orientation of guest molecules originates from not only the kinetic relaxation but also the kinetic stability of the deposited guest molecules on the film surface during film growth. Utilizing the ultimate orientation, a highly efficient organic light-emitting diode with the external quantum efficiency of 33.4 ± 2.0% was realized. The thermal stability of the horizontal orientation of cis-BOX2 was governed by the glass transition temperature (Tg) of the CBP host matrix; the horizontal orientation was stable unless the film was annealed above Tg.
AB - A complete horizontal molecular orientation of a linear-shaped thermally activated delayed fluorescent guest emitter 2,6-bis(4-(10Hphenoxazin-10-yl)phenyl)benzo[1,2-d:5,4-d′] bis(oxazole) (cis-BOX2) was obtained in a glassy host matrix by vapor deposition. The orientational order of cis-BOX2 depended on the combination of deposition temperature and the type of host matrix. Complete horizontal orientation was obtained when a thin film with cis-BOX2 doped in a 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) host matrix was fabricated at 200 K. The ultimate orientation of guest molecules originates from not only the kinetic relaxation but also the kinetic stability of the deposited guest molecules on the film surface during film growth. Utilizing the ultimate orientation, a highly efficient organic light-emitting diode with the external quantum efficiency of 33.4 ± 2.0% was realized. The thermal stability of the horizontal orientation of cis-BOX2 was governed by the glass transition temperature (Tg) of the CBP host matrix; the horizontal orientation was stable unless the film was annealed above Tg.
UR - http://www.scopus.com/inward/record.url?scp=84975318412&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84975318412&partnerID=8YFLogxK
U2 - 10.1063/1.4954163
DO - 10.1063/1.4954163
M3 - Article
AN - SCOPUS:84975318412
SN - 0003-6951
VL - 108
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 24
M1 - 241106
ER -