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In recent years, several strategies have been proposed and demonstrated to enhance the efficiency of organic light-emitting diodes (OLEDs) and organic photovoltaics (OPVs). In both types of devices, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is commonly used to enhance hole injection. The layer is further designed by incorporating metallic-based, carbon-based, organic, inorganic, and hybrid nanoparticles with the aim of improving the performance and hence the efficiency through the improvement of light out-coupling in OLEDs and enhancement in light absorption generation of hole-charge carriers in OPVs. This review elucidates the use of different types of nanoparticles that are doped into PEDOT:PSS and their effects on OLEDs or OPVs. The effects include surface plasmon resonance (SPR), scattering, better charge transport, improvement in surface morphology and electrical properties of PEDOT:PSS. Promising results have been obtained and can potentially lead to low cost, large-area manufacturing process.

Indium tin oxide (ITO) is the most important transparent conducting electrode to date and the candidate for ultrafast signal processing in telecommunication region. ITO is normally selectively removed in a multiple-steps process for device application. In this work, we aimed to study single pulse removal of ITO-coated glass and PET by using a nanosecond (ns) laser (266 nm) and a femtosecond (fs) laser (1,025 nm) where each process is dominated by either linear or nonlinear process. For ns laser, ITO was removed from PET substrate at 0.01 J/cm2. Detachment likely occurred via thermal-induced process because of the high absorption by both ITO and PET and the thermomechanical properties of PET. At higher laser fluence (∼0.04 J/cm2), the ITO films on both substrates were damaged, and at 1.34 J/cm2, ITO was ablated from the glass substrate. For fs laser removal via nonlinear process, ITO was removed from PET substrate at 0.3 J/cm2, but at 0.8 J/cm2, the PET substrate was also modified. ITO layer was partially removed from glass substrate by fs laser pulse at 0.3 J/cm2 and full removal only occurred at 1.7 J/cm2. Thus, the fluence range for single fs pulse removal of ITO/PET was 0.3–0.8 J/cm2 and >1.7 J/cm2 for ITO/glass.

Low-temperature growth of indium tin oxide (ITO) nanowires (NWs) was obtained on catalyst-free amorphous glass substrates at 250 °C by Nd:YAG pulsed-laser deposition. These ITO NWs have branching morphology as grown in Ar ambient. As suggested by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), our ITO NWs have the tendency to grow vertically outward from the substrate surface, with the (400) plane parallel to the longitudinal axis of the nanowires. These NWs are low in electrical resistivity (1.6×10⁻⁴ Ω cm) and high in visible transmittance (~90–96%), and were tested as the electrode for organic light emitting devices (OLEDs). An enhanced current density of ~30 mA cm⁻² was detected at bias voltages of ~19–21 V with uniform and bright emission. We found that the Hall mobility of these NWs is 2.2–2.7 times higher than that of ITO film, which can be explained by the reduction of Coulomb scattering loss. These results suggested that ITO nanowires are promising for applications in optoelectronic devices including OLED, touch screen displays, and photovoltaic solar cells.