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A novel surface modifier, ethylenediamine tetraacetic acid tetrasodium salt (EDTNa), was incorporated on the surface of TiO2, and the resulting electrodes were applied to the photoanode of dye-sensitized solar cells (DSSCs). The DSSC with EDTNa-incorporated photoelectrode showed an increase in short-circuit current (JSC) and open-circuit voltage (VOC), resulting in a 16.5% enhancement in power conversion efficiency, compared to that of reference cell without EDTNa. It was found that the presence of the bulky ethylenediamine tetraacetate moieties increases lifetime of electrons injected from dye molecules to TiO2, resulting from an effective prevention of direct contact between electrolyte ions and the TiO2 surface. This improvement of lifetime induced the enhancement in J, and VOC.

The surface of TiO2 photoelectrodes coated on F-doped SnO2 (FTO) was modified by soaking it in a TiCl4:AlCl3 mixed aqueous solution with various molar ratios, and then calcining to produce the TiCl4:AlCl3-treated TiO2 photoelectrode (Ti:Al-TiO2/FTO). The highest power conversion efficiency (PCE) was obtained from dye-sensitized solar cells (DSSC) with Ti:Al(5:5)-TiO2/FTO, which was prepared from the mixed solution with the molar ratio of 5:5 (TiCi4:AlCl3). PCE of DSSC with Ti:Al (5:5)-TiO2/FTO was improved by ca. 19.6%, compared to that of the reference device with Ti:Al (10:0)-TiO2/FTO (i.e., TiO2-coated TiO2/FTO) due to an enhancement in both short-circuit photocurrent (J(sc)) and open-circuit voltage (V(oc)). A series of measurements such as UV-visible absorption, electrochemical impedance, open circuit voltage decay and dark current revealed that the increase in J(sc) was attributed to the improvement of electron collection efficiency by a prolonged electron lifetime, and the suppression of the charge recombination between injected electrons and I3(-) ions was found to increase the V(oc) value of the device with Ti:Al(5:5)-TiO2/FTO.

To improve the operation lifetime of organic solar cell, two different diphenylacetylene polymers were tested as UV blocking layer. One of them showed either stronger UV absorption or a relatively intense fluorescence emission in the visible region which is well overlapped with the absorption of P3HT in the OSC. The diphenylacetylene polymer film significantly improved the operation lifetime of the OSC by efficiently absorbing the UV light, while reducing the UV-light energy loss to a minimum by converting the UV light to visible light through a down-conversion process.

Electrospinning has recently emerged as a leading technique for the formation of nanofibrous structures made of organic and inorganic components. In this study, nanofibrous scaffolds were prepared by electrospining a bend solution of poly(L-lactide-co-glycolide) (PLGA) and silver nanoparticles in 1,1,1,3,3,3,-hexafluoro-2-propanol (HFIP). The resulting fibers ranged from 420 to 590 nm in diameter. To evaluate the possibility of using silver-containing PLGA as a tissue engineering scaffold, experiments on cell viability and antibacterial activity were carried out. As a result, PLGA nanofibrous scaffolds having silver nanoparticles of more than 0.5 wt% showed antibacterial effect against Staphylococcus aureus and Klebsiella pneumonia. Furthermore, silver-containing PLGA nanofibrous scaffolds showed viability, indicating their possible application in the field of tissue engineering.