Browsing by Subject "Platinum electrodes"

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Open Access
Conducting polymer composites of polypyrrole and polyindene
(Elsevier, 1996) Bozkurt, A.; Akbulut, U.; Toppare, L.
Polypyrrole-polyindene composites were prepared via electrochemical methods. Two different approaches were utilized. In the first, the electro-initiated polymerization of indene on a platinum electrode was achieved at 2.0 V versus Ag/Ag+ in acetonitrile. Then the polyindene-coated electrode was used for the electrochemical polymerization of pyrrole at 1.0 V versus Ag/Ag+. In the second case, electrochemical coating of platinum electrode with polypyrrole at 1.0 V versus Ag/Ag+ was carried out and indene was polymerized on the conducting polymer at 2.0 V versus Ag/Ag+ in acetonitrile medium. The characterizations of these composites were done by FT-IR, scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). Electrical conductivities were evaluated by two-probe and four-probe methods.
Open Access
High performance infrared photodetectors up to 2.8 μm wavelength based on lead selenide colloidal quantum dots
(OSA - The Optical Society, 2017) Thambidurai, M.; Jang, Y.; Shapiro, A.; Yuan, G.; Xiaonan, H.; Xuechao, Y.; Wang, Q. J.; Lifshitz, E.; Demir, Hilmi Volkan; Dang C.
The strong quantum confinement effect in lead selenide (PbSe) colloidal quantum dots (CQDs) allows to tune the bandgap of the material, covering a large spectral range from mid- to near infrared (NIR). Together with the advantages of low-cost solution processability, flexibility and easy scale-up production in comparison to conventional semiconductors especially in the mid- to near infrared range, PbSe CQDs have been a promising material for infrared optoelectronic applications. In this study, we synthesized monodisperse and high purity PbSe CQDs and then demonstrated the photodetectors working at different wavelengths up to 2.8 μm. Our high quality PbSe CQDs show clear multiple excitonic absorption peaks. PbSe CQD films of different thicknesses were deposited on interdigitated platinum electrodes by a simple drop casting technique to make the infrared photodetectors. At room temperature, the high performances of our PbSe CQD photodetectors were achieved with maximum responsivity, detectivity and external quantum efficiency of 0.96 A/W, 8.13 × 109 Jones and 78% at 5V bias. Furthermore, a series of infrared LEDs with a broad wavelength range from 1.5 μm to 3.4 μm was utilized to demonstrate the performance of our fabricated photodetectors with various PbSe CQD film thicknesses.