Synthesis and characterization of fluorene‐based copolymers containing benzothiadiazole derivative for light‐emitting diodes applications

Abstract

Five new thermally robust electroluminescent fluorene-based conjugated copolymers, including poly[2,7-(9,9-dioctylfluorene)-co-4,7-{5,6-bis(3,7-dimethyloctyloxymethyl)-2,1,3-(benzothiadiazole)}] (PFO-P2C 10 BT) were synthesized and used to fabricate the efficient polymer light-emitting diodes (PLEDs). The glass transition temperatures of the polymers were found to be higher than that of poly(9,9-dialkylfluorenes) and are in the range 113-165 C. We fabricated PLEDs in indium-tin oxide/ PEDOT/light-emitting polymer/cathode configurations using either double-layer LiF/Al or triple-layer Alq 3 /LiF/Al cathode structures. The new copolymers were found to have emission colors that vary from greenish blue (491 nm) to green (543 nm) depending on the copolymer composition. The maximum brightness and luminance efficiency of these PLEDs were found to be up to 5347 cd/m 2 and 1.51 cd/A at 10 V, respectively. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: [6762][6763][6764][6765][6766][6767][6768][6769] 2008

Synthesis and Characterization of 1,2,4-Oxadiazole-Based Deep-Blue and Blue Color Emitting Polymers

“…Light emitting co-monomer M1 was synthesized according to the procedure repported. 5 The Suzuki polycondensation reaction between monomer M1 and BOB or monomer M1 and TOT followed by end capping afforded two new alternating copolymers PFBOB and PFTOT, respectively.…”

“…[4][5][6][7][8] However, most of the emissive -conjugated polymers are -excessive in nature, and consequently, those polymers are found to transport the holes more efficiently than electrons. The charge imbalance of the -conjugated polymers is considered as the most important limiting factor for the PLEDs device performnces.…”

“…3 It is well known that the light-emitting properties of fluorene-based polymers are usually tuned by incorporating different -conjugated chromophores on their main chain. [4][5][6][7][8] The tunable lightemitting properties of fluorene-based polymers might be the reason for their wide applications in PLEDs and fluorogenic chemosensors.…”

In-situ fabricated transparent conducting nanofiber-shape polyaniline/coral-like TiO2 thin film: Application in bifacial dye-sensitized solar cells

“…The catalytic activity and transparency of conducting polymers such as poly (9,9-dioctylfluorene-co-benzothiazole) (F8BT) [15], poly (3,4-ethylenedioxythiophene) (PEDOT) [16], poly (9,9-dioctylfluorene) (PFO) [17], poly (phenylene vinylene) (OxdEh-PPV) [18], 2,2′-bis (3,4-ethylenedioxythiophene) [19] and polyaniline (PANI) has been studied for their favorable electrical conductivity and high catalytic activity to replace the opaque carbon-based and expensive Pt-based CE [20]. For instance, PEDOT doped with poly(styrenesulfonate) (PEDOT:PSS) has emerged as a promising CE because of its suitable mechanical stability and easy processability.…”

Synthesis, photophysics, and electroluminescent performance of stable blue‐light‐emitting copoly(9,9‐diarylfluorene)s

“…Polyfluorene with large band gaps has emerged as very promising material for blue emission because of its unique combination of excellent chemical and thermal stability as well as photostablility, high photoluminescence (PL) quantum yield, and easy fabrication and processing 10, 11. In addition, polyfluorene derivatives were also used as host materials to blend with low‐band‐gap emitters to obtain various emission colors 12–22. Furthermore, several reports presented the white‐light‐emitting devices from polyfluorene derivatives by introducing orange‐ or green‐ and red‐light chromophores 23–30.…”