TY - GEN
T1 - Charge balance conductive vinyl polymers for homojuncton organic light emitting diodes (OLEDs)
AU - Leung, Louis M.
AU - Wang, Jianli
AU - Wong, Michael Y.
AU - Law, Y. C.
AU - Lai, K. M.
AU - Lee, T. H.
PY - 2012
Y1 - 2012
N2 - Several series of bipolar small molecules have been synthesized and studied as charge balancing materials for homojunction OLED applications. 1-3The bipolar molecules consisted of several components including a hole transporting arylamine moiety, an electron transporting oxadiazole moiety and an emitting polycyclic aromatic moiety. The achievement of charge balance was confirmed via time-of-flight (TOF) mobility measurements and/or optimum device performances. The same arylamine, oxadiazole, and polycyclic aromatic moieties have been converted to vinyl monomers via a Vilsmeyer formylation and then a Wittig coupling reaction.4 The different vinyl monomers were then copolymerized to produce a range of conductive vinyl copolymers. The transport and emission properties of the copolymers were found relating to the chemistry of the respective monomers and overall copolymer compositions. The achievement of charge balance and their applications in homojunction OLEDs have been investigated. In this paper, several series of conductive vinyl polymers shall be discussed including the followings. (i) The first is a series of hole transporting poly(N-phenyl-N-styryl-1- naphthylamine) (PNPA) with different substituted group on the benzene ring.4Their holes mobilities were measured to be 0.5-2 × 10-4 cm2 V -1s-1. (ii) The second series is copolymers of hole transporting N-(4-methoxyphenyl)-N-(4-vinylphenyl) naphthalen-1-amine (MeONPA) and electron transporting 2- phenyl-5-(4-vinylphenyl)-1,3,4-oxadiazole (OXA) which has been applied as a hole limiting layer for devices containing oxidative degradating Alq3. 5 At the optimum charge balance composition with Alq3 as the emitting layer, the optimum current efficiency and luminance were 4.2 cd/A and 24,000 cd/m2 with extented device life-time. (iii) The third series is copolymers prepared from MeONPA and 1-vinylpyrene (py) at different compositions.6 Homojunction devices were prepared with highest luminance and current efficiency at 2,270 cd/m2 and 1.32 cd/A. The emission color, however, shifted from greenish to bluish pending on the composition of the π-stackable and exciplexes forming pyrene moieties. (iv) The fourth copolymer series is terpolymers containing perylene as the emitters, and 4MeONPA and OXA as the charge transporting moieties. A greenish luminance of 760 cd/m2 was achieved for the terpolymer with only 0.6 mol % perylene contents.
AB - Several series of bipolar small molecules have been synthesized and studied as charge balancing materials for homojunction OLED applications. 1-3The bipolar molecules consisted of several components including a hole transporting arylamine moiety, an electron transporting oxadiazole moiety and an emitting polycyclic aromatic moiety. The achievement of charge balance was confirmed via time-of-flight (TOF) mobility measurements and/or optimum device performances. The same arylamine, oxadiazole, and polycyclic aromatic moieties have been converted to vinyl monomers via a Vilsmeyer formylation and then a Wittig coupling reaction.4 The different vinyl monomers were then copolymerized to produce a range of conductive vinyl copolymers. The transport and emission properties of the copolymers were found relating to the chemistry of the respective monomers and overall copolymer compositions. The achievement of charge balance and their applications in homojunction OLEDs have been investigated. In this paper, several series of conductive vinyl polymers shall be discussed including the followings. (i) The first is a series of hole transporting poly(N-phenyl-N-styryl-1- naphthylamine) (PNPA) with different substituted group on the benzene ring.4Their holes mobilities were measured to be 0.5-2 × 10-4 cm2 V -1s-1. (ii) The second series is copolymers of hole transporting N-(4-methoxyphenyl)-N-(4-vinylphenyl) naphthalen-1-amine (MeONPA) and electron transporting 2- phenyl-5-(4-vinylphenyl)-1,3,4-oxadiazole (OXA) which has been applied as a hole limiting layer for devices containing oxidative degradating Alq3. 5 At the optimum charge balance composition with Alq3 as the emitting layer, the optimum current efficiency and luminance were 4.2 cd/A and 24,000 cd/m2 with extented device life-time. (iii) The third series is copolymers prepared from MeONPA and 1-vinylpyrene (py) at different compositions.6 Homojunction devices were prepared with highest luminance and current efficiency at 2,270 cd/m2 and 1.32 cd/A. The emission color, however, shifted from greenish to bluish pending on the composition of the π-stackable and exciplexes forming pyrene moieties. (iv) The fourth copolymer series is terpolymers containing perylene as the emitters, and 4MeONPA and OXA as the charge transporting moieties. A greenish luminance of 760 cd/m2 was achieved for the terpolymer with only 0.6 mol % perylene contents.
KW - 3-(4-vinylphenyl)perylene
KW - Charge balance
KW - Conductive vinyl polymers
KW - Homojunction OLEDs
UR - http://www.scopus.com/inward/record.url?scp=84870705704&partnerID=8YFLogxK
U2 - 10.1109/SCET.2012.6341992
DO - 10.1109/SCET.2012.6341992
M3 - Conference proceeding
AN - SCOPUS:84870705704
SN - 9781457719646
T3 - 2012 Spring World Congress on Engineering and Technology, SCET 2012 - Proceedings
BT - 2012 Spring World Congress on Engineering and Technology, SCET 2012 - Proceedings
T2 - 2012 Spring World Congress on Engineering and Technology, SCET 2012
Y2 - 27 May 2012 through 30 May 2012
ER -