This study used natural dyes as sensitizers of dye-sensitized solar cells (DSSCs) to replace expensive chemical synthetic dyes. We prepared two natural dyes, chlorophyll dye and anthocyanin dye, by extracting them from wormwood and purple cabbage, respectively. Moreover, we mixed the prepared chlorophyll dye and anthocyanin dye at 5 different volume ratios to form cocktail dyes. For preparation of photoelectrode, P25 TiO2nanoparticles were used to prepare paste, which was coated on fluorine-doped tin oxide (FTO) conductive glass by the spin coating method at different spin coating speeds in order to form TiO2thin films with different thicknesses. The DSSC prepared by the cocktail dye achieves photoelectric conversion efficiency (η) of 1.95%, open-circuit voltage (VOC) of 0.765 V, and short-circuit current density (JSC) of 5.83 mA/cm2. Moreover, the prepared DSSC sensitized solely by chlorophyll extract of wormwood achieved a photoelectric conversion efficiency (η) of 0.9%, whereas the DSSC sensitized solely by anthocyanin extract of purple cabbage achieved a photoelectric conversion efficiency of 1.47%, achieving the longest lifetime of electrons amongst these three dyes.

service Email alerting click here top right corner of the article or Receive free email alerts when new articles cite this article -sign up in the box at the http://esl.ecsdl.org/subscriptions go to: Electrochemical and Solid-State Letters To subscribe toA bipolar resistive switching memory device with a low power operation ͑200 A ϫ 1.3 V͒ in a W/Ge 0.4 Se 0.6 /Cu/Al structure is investigated. A high quality Ge 0.4 Se 0.6 solid electrolyte is confirmed by X-ray photoelectron spectroscopy. The resistive memory device with a small via size of 0.2 m has a large threshold voltage of Ͼ0.4 V, high resistance ratio ͑R high /R low ͒ of Ͼ10 2 , and good uniformity. The switching mechanisms are due to the Cu metallic filament formation and dissolution from the Ge 0.4 Se 0.6 solid electrolyte under positive and negative biases, respectively, which have been confirmed by high resolution transmission electron microscopy image and energy-dispersive X-ray spectroscopy analysis. The strong Cu filament formation can also be investigated by monitoring the erase voltage and erase current. Good endurance of Ͼ10 5 cycles is obtained. Excellent data retention characteristics at 85°C are observed after 24 h of retention time, owing to the strong Cu metallic filament formation in the Ge 0.4 Se 0.6 solid electrolyte.

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