In this letter, we report an oleic acid ͑OA͒-capped CdSe quantum-dot sensitized solar cell ͑QDSSC͒ with an improved performance. The TiO 2 / OA-CdSe photoanode in a two-electrode device exhibited a photon-to-current conversion efficiency of 17.5% at 400 nm. At AM1.5G irradiation with 100 mW/ cm 2 light intensity, the QDSSCs based on OA-capped CdSe showed a power conversion efficiency of about 1%. The function of OA was to increase QD loading, extend the absorption range and possibly suppress the surface recombination.

We report a quantum dot sensitized solar cell (QDSSC) with a thioglycolic acid (TGA) capped CdSe quantum dot (QD) sensitized ZnO nanorod photoanode. As revealed by UV-Vis absorption spectrum and transmission electron microscopy, the quantum dots can be effectively adsorbed onto ZnO nanorods. By studying the emission decay, the quenching of the CdSe QDs by ZnO nanorod was verified, and an electron transfer (from QD to ZnO) rate constant of 1 x 10(8) s(-1) was obtained. The efficiency of the as-prepared QDSSC was 0.66% and an incident power conversion efficiency of 22% at 400 nm was achieved.

a b s t r a c tWe report a fast-switching negative photoelectrochromic cell composed of a dye-sensitized nanocrystalline TiO 2 electrode and Prussian blue counter electrode sandwiching a LiI electrolyte. The cell can be bleached under illumination with shorted TiO 2 and Prussian blue electrodes, and re-colored by applying an appropriate external voltage. The photo-bleaching and electric-coloring processes are fast and reversible. A maximum absorbance modulation of 0.44 recorded at 700 nm is obtained between bleached and colored states for the cell when the PB film's thickness is 452 nm. Illuminated under different levels of light intensity or durations of time, the shorted cell shows adjustable optical absorption from 470 to 840 nm. The in-situ transmittance response depicts that the photo-bleaching response is 6.2 s for 70% transmittance change under 100 mW/cm 2 illumination in short circuit configuration, and the re-coloration time is about 600 ms under 2 V bias recorded at 780 nm, with an electrochromic coloration efficiency of 103.4 cm 2 /C. The cell shows a good reversible stability and can be potentially applied in erasable displays.

In this paper, a calibration-free wavelength modulation model via tunable diode laser absorption spectroscopy was setup. The laser modulation characteristics, modulation depth, linear modulation amplitude and frequency shift, were measured for the model setup. The experimental results show that modulation depth and the linear intensity modulation amplitude have well linear fitting to the scan voltage. Based on the laser parameters, the calibration-free model can be used to infer the gas temperature.

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