Hole transporting polymer

SCHEME 3.19 Chemical structure of cross-linkable hole transport polymer. 

HOMO energy level of the polymer is 5.32 eV. It was demonstrated that the EL performance of super yellow PPV and blue polyfluorene derivatives using this hole transport polymer is comparable to or better than that using PEDOT PSS as a HTL [102],... 

Research Focus Synthesis of poly( fluorene-co-triphenylamine) derivatives as hole transport polymers. 

Monomers, (III) and (IV), having pendant tri ary I methane groups were prepared by Herron et al. (3) and then free radically polymerized and used as hole transport polymers. 

Scheme 1 Some hole transport polymers (a) and (b), and sensitizers (c) and (d) that are used in composite PR materials.

Title Hole Transport Polymers and Devices Made with Such Polymers... 

Just as described for LEDs in the preceding section, the area of the heterojunction in solar cells with the planar structure shown in Fig. 10.3(a) is defined by the dimensions of the cell. Similarly, this area is dramatically increased by the use of blends of immiscible electron- and hole-transporting polymers (Moons, 2002). Carriers generated at the dispersed interface between the two polymers will be able to diffuse to the electrodes if the network contains... 

Figure 18. A selection of organic hole-transporting polymers or glasses for photorefractives.

Heeney M., Zhang W., Crouch D. J., Sparrowe D., Hamilton R., Higgins S., Skabara P. and McCulloch 1. (2007), Regioregular poly(3-hexyl)selenophene a low band-gap organic hole transporting polymer , Adv. Mat. (submitted). 

Recently, several photoactive polymers have been examined that fit these criteria. They include JV-polyvinylcarbazole (PVK) [101,102], (phenyl-methyljpolysilane (PMPS) [103], and amine-doped polycarbonate [104], All are known hole-transporting polymers. A large number of semiconductor nanoclusters can be doped into these polymers and interact with the polymer and facilitate carrier injection into the polymer [101-104]. Dramatic enhancement in charge generation efficiency has been observed. The availability of these semiconductor nanocluster/polymer composites opens the doorway for exploring transport-related applications. In the following sections, I review their photoconductive properties and discuss possibilities in other related areas. 

Phthalocyanine and naphthalocyanine are guest dye dopants suitable for the near infrared (IR) region. PVK is used as usual, as the hole transport polymer, Alqs, or a sulforamide derivative (Al(qs)3) is used as the host dye. The absorbance spectra of the guest dyes are significantly different from the emission spectra of the host dyes. However, the high molar absorption of the host dye dopants result in such efficiencies of energy transfer that are comparable to quinacridone or rubrene dopants. 

Poly(siloxane)s. An alternative to PVK is the hole-transporting polymer poly(methyl-bis-(3-methox5 henyl)-(4-propylphenyl)amine)siloxane. It has been doped with the photorefractive chromophore 4-di(2-methoxy-ethyl) aminobenzylidene malononitrile. The low intrinsic glass transition temperature of the siloxane pol5mier allows the preparation of samples without additional plasticizers. The composites exhibit good chromophore orientational mobility and exhibit photorefractive response times in the millisecond range. ... 

FIGURE 5.18 PVK is a hole-transporting polymer commonly mixed with the electron transport molecule PBD and used as a host in electrophosphorescent devices. 

Polyquinolines and polyquinoxalines are n-type (electron transporting) polymers and therefore offer alternative EL device engineering in conjunction with the extensively studied p-type (hole transporting) polymers such as poly(p-phe-nylene vinylene)s, polyphenylenes, and polythiophenes. A variety of polyquinolines [331,332] and polyquinoxalines [333] has been reported in the literature, acting as the active... 

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