Nanotube and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) composite film for the electrode applications in organic thin-film transistor and dye-sensitized solar cells.

In this study, composite films made of coiled carbon nanotubes (CCNTs) and poly(3,4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) (PEDOT:PSS) were fabricated with different composition ratios. The variations in film properties (including surface morphology, work function, and electrical conductivity) in accordance with the amount of CCNT dosing were investigated. Subsequently, through HCl-methanol treatment, we achieved a significant enhancement in electrical conductivity with little damage to the CCNT features. The characteristics of CCNT/PEDOT:PSS composite film are generally comparable to those of PEDOT:PSS film, and some of them, such as catalytic activity and work function, are significantly higher. On the basis of these versatile features, the CCNT/PEDOT:PSS composite films exhibit excellent performance as source/drain electrode in organic thin-film transistors and as catalytic counter electrode in dye-sensitized solar cells.

Effects of postannealing process on the properties of RuO2 films and their performance as electrodes in organic thin film transistors or solar cells.

RuO(2) films were deposited on SiO(2) (300 nm)/N++Si substrates using radio frequency magnetron sputtering at room temperature. As-deposited RuO(2) films were annealed at different temperatures (100, 300, and 500 °C) and ambients (Ar, O(2) and vacuum), and the resulting effects on the electrical and physical properties of RuO(2) films were characterized. The effect of annealing atmosphere was negligible, however the temperature highly influenced the resistivity and crystallinity of RuO(2) films. RuO(2) films annealed at high temperature exhibited lower resistivity and higher crystallinity than as-deposited RuO(2). To investigate the possibility to use RuO(2) film as alternative electrodes in flexible devices, as-deposited and annealed RuO(2) films were applied as the source/drain (S/D) electrodes in organic thin film transistor (OTFT), catalytic electrodes in dye sensitized solar cell (DSSC) and as the hole-injection buffer layer (HIL) in organic photovoltaic (OPV). Except for OTFTs (µ ≈ 0.45 cm(2)/(V s) and on/off ratio ≈ 5× 10(5)) with RuO(2) S/D electrodes, the DSSC and OPV (3.5% and 2.56%) incorporating annealed RuO(2) electrodes showed higher performance than those with as-deposited RuO(2) electrodes (3.0% and 1.61%, respectively).