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Electron transfer layer (ETL) is vital importance for obtaining high performance perovskite solar cells (PSC). This can be achieved by producing tin oxide (SnO2) ETL, which is produced at high temperature, has appropriate energy band alignment, high optical transmittance and high carrier mobility. ETL produced at low temperature generally has low crystallization, poor electron mobility, and abundant defects at grain boundaries. This prevents efficient load transport, creates recombination and causes serious energy losses. In this paper, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid (IL) was added into SnO2 ETL in different concentrations to improve these negative properties caused by the production of SnO2 ETL at low temperature, using spin-coater technique at low temperature (100 °C) was prepared. Optical properties of EMIMBF4 IL doped SnO2 ETL and perovskite films were investigated using UV-vis-NIR spectrometry and photoluminescence spectrophotometer (PL) measurement. The surface morphology of the produced films was investigated by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The crystal structure analysis of the films was carried out by X-ray diffraction (XRD). The hydrophilic/hydrophobic behavior of the surfaces was evaluated using contact angle measurement. It has been observed that EMIMBF4 doped SnO2 ETL films have fewer surface defects by passivation of surface defects compared to pure SnO2 ETL film and they crystallize at a relatively low and economical temperature (100°C). It has been determined that 0.5% EMIMBF4 doped films give better optical and structural results than other doped and pure ETL films, albeit low. [ABSTRACT FROM AUTHOR]

Organic solar cells are one of the alternative energy sources. The only barrier to commercialization of this technology is its low efficiency values. In this study, the efficiency of inverted organic solar cells was increased by utilizing the plasmonic effects of Ag nanoparticles (np). The device configuration is ITO/ZnO/poly(3-hexylthiophene-2,5-diyl) (P3HT):(6,6)-phenyl C61 butyric acid methyl ester (PCBM)/MoO3/Ag. Ag np's were synthesized by polyol method and characterized by X-Ray diffractometry (XRD), Uv-Vis spectrophotometer and field emission scanning electron microscopy (FESEM). Afterwards, Ag was added to P3HT:PCBM at the ratios of 0.125-0.25-0.5% by mass. While the efficiency value was 3.21% in the reference cell, it reached 3.43% with an increase of approximately 7% in the 0.25% Ag added device. [ABSTRACT FROM AUTHOR]

In this work, Co3O4 nanoneedle arrays on nickel foam (Co3O4/Ni foam) were directly synthesized by facile one step thermal treatment. The structural and morphological analysis of Co3O4/Ni foam nanocomposites were characterized by X-ray diffraction spectroscopy (XRD) and field emission scanning electron microscopy (FESEM). The electrochemical oxidation of methanol on Co3O4/Ni foam in alkaline solution was investigated by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. The Co3O4/Ni foam showed excellent electrocatalytic performance with low onset potential (270 mV), high current density (67 mA cm-2 ) and long electro-oxidation stability (86%). Thus, it has been determined that the synthesized nanocomposite can be an excellent candidate for high performance platinum-free electrocatalysts directly for methanol fuel cells. [ABSTRACT FROM AUTHOR]

In this study; a flexible, self-contained and durable PtCu/reduced graphene oxide (iGrO) hybrid paper was synthesized and used for the electrochemical detection of p-nitrophenol (PNP). PtCu/iGrO hybrid paper was fabricated through electrodeposition of PtCu composite structure on iGrO paper electrode. The obtained PtCu/iGrO hybrid paper was characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, electrochemical impedance spectroscopy. The morphological analysis of PtCu/iGrO hybrid paper showed that flower-like nanostructures formed on the iGrO electrode surface consist of numerous sharp-edged nano layer of PtCu. PtCu/iGrO hybrid paper electrode demonstrated high electrocatalytic performance compared to iGrO paper and exhibited a wide linear range (0.08-760 μM) and a low detection limit (0.022 μM) for the determination of PNP. The PtCu/iGrO hybrid paper sensor also showed high recovery values for PNP detection in tap water. The hybrid paper sensor prepared with a practical and easy-to-apply method exhibited mechanically flexible and durable properties. Moreover, stability tests of PtCu/iGrO paper displayed that this hybrid electrode is an important candidate for high-performance flexible sensor applications. [ABSTRACT FROM AUTHOR]