Organic solvent processable OligotronTM conducting triblock copolymers for microelectronics: functional end-caped conducting oligomers

Over the past several years, TDA Research, Inc. has been developing solvent processable forms of poly(3,4-ethylenedioxythiophene) commonly known as "PEDOT". Our approach is to make block copolymers with alternating conducting and non-conducting blocks. The conducting segments provide the electronic properties, while the non-conducting segments are designed to promote dispersion. TDA has two lines of conducting polymer products named Aedotron and Oligotron, and this paper focuses on our family of ABA end-capped oligomers (trade named Oligotron). These capped oligomers have a center block consisting of PEDOT and two non-conducting end-capping blocks, which can contain polymerizable methacrylate groups (see Figure 1). Oligotron oligomers are dispersible in non-corrosive organic solvents and can be used to dip coat, spin coat or print thin films for electronic devices. The oligomers that have polymerizable methacrylate groups in the endcaps, can theoretically be printed using a lithographic technique by crosslinking the oligomers at the methacrylate groups to render them fixed in place. Alternatively, the organic dispersion containing the conducting oligomers can be formulated into inks for inkjet printing with a post photo-initiated or thermal-initiated curing step. These printing techniques could potentially be used to produce detailed patterns of PEDOT conducting materials for microelectronic applications. TDA Research has made quantities of the methacrylate end-capped oligomer (compound 2 in Figure 1) commercially available for research and development through Sigma-Aldrich as a dispersion in either propylene carbonate or nitromethane. (The propylene carbonate dispersion is Aldrich product number 649813, and the nitromethane is number 649821.)