Papers by Keyword: Solar Cell

Abstract: In this paper, a novel photosynthetic bacteria solar cell with Rhodopseudomonas as the electricity generation bacteria was designed and prepared, and photo current changing with the time of the cell was investigated by testing current-time（i-t） curve under alternating light and dark. The results showed that the maximum photo current of the cell could be 13 μA. The influence of glucose, sucrose, chitosan, anthraquinone and hydroquinone on the photo current was investigated. The results indicated that glucose and chitosan made the photo current of solar cell increased about 21 μA and 27 μA, respectively; but sucrose, anthraquinone or hydroquinone had not such effect. It illustrated that photo electrons could be emitted by Rhodopseudomonas and were transmitted to the anode of the cell in the presence of electronic media under light, and the photo current could be improved further by the adding of some additives.

Abstract: The self-organized hollow TiO₂ hemisphere with a height of 130 nm and a diameter of 200 nm was formed. Highly ordered TiO₂ nanotube arrays of 200-nm pore diameter and 700-nm length were grown perpendicular to a FTO substrate by infiltrating the alumina pores with Ti (OC₃H₇)₄ which was subsequently converted into anatase TiO₂. The structure was treated with TiCl₄ to enhance the photogenerated current and then integrated into the DSSC using a commercially available ruthenium-based dye. The dye-sensitized solar cell using self-organized hollow TiO₂ hemispheres under porous alumina with TiO₂ nanotubes inside as the working electrode generated a photocurrent of 5.00 mA/cm², an open-circuit voltage of 0.58 V and yielding a power conversion efficiency 1.77 times the conventional nanoparticle-based DSSC.

Abstract: A low cost and simple fabrication of Cu-In-Se polycrystalline thin film for copper indium diselenide solar cell was prepared in a two-step process. The first step, a Cu In precursor film was prepared from copper acetate monohydrate and indium acetate mixed solution. The solution was coated on molybdenum-coated soda lime glass using the spin coating technique at room temperature following annealing in air at 500^°C for 20 minutes. The effect between spin parameters and film thickness of as-deposited Cu-In film were investigated. The second step, selenium was added in the precursor film by selenization process at 450^°C in Se atmosphere for 30 minutes in a low vacuum tube furnace with background pressure of 10^-2 mbar. The crystallographic properties of Cu-In-Se thin films were identified by X-ray diffractometer (XRD), the surface and cross-sectional morphology of films were observed by scanning electron microscopy (SEM). The chemical compositions of films were characterized by energy dispersive spectroscopy (EDS). It was found that the thickness of Cu-In films deposited on molybdenum-coated soda lime glass were approximately 1 μm. The EDS analysis showed the composition ratio in atomic % of Cu/In as approximately as 0.77. The XRD results reveal that the as-deposited Cu-In films consist of a mixture of copper oxide (CuO) and indium oxide (In₂O₃) phase at the annealing temperature of 500^°C. Furthermore, CuO and In₂O₃ phase were converted to (112) oriented chalcopyrite copper indium diselenide after selenization process.

Abstract: The aim of this study was to investigate the localized solar cells heating by thermal imaging, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrical measurements and thermal infrared measurements were done on the commercial crystalline Si cells (10 cm x 10 cm). SEM was used for the observation of the localized heating. The I-V characteristics of all cells were quite similar with a small spread in the electrical parameters, while the IR images were different: some cells had quite uniform temperature profiles distribution and other ones showed the localized heating. The energy dispersive spectroscopy (EDS) analysis showed that some hot spots have high metal impurity contamination. The micro-structure investigation of hot spots revealed the micro-cracks presence. Our study found direct correlation between areas of high impurity contamination, micro cracks and hot-spot heating.

Abstract: Polymer blends are potential candidates for solar-energy conversion, due to their flexibility, ease of processing, and low costs. We report herein 2.6 cm² active area of flexible polymer solar cells based on blends of polymeric semiconductor [poly (2-methoxy-5-(3,7-dimethyloctyloxy)-(para-phenylene vinylene)] (MDMO-PPV) and the soluble fullerene C60 derivative [6,6 phenyl C61-butyric acid methyl este (PCBM). Devices were prepared by etching an electrode pattern of Indium Tin Oxide (ITO) covered on poly [ethylene terephthalat (PET) substrate. A layer of conducting poly (3,4-ethylenedioxythiophene):poly (styrene sulphonate) (PEDOT:PSS) were screen printed on top of the ITO. Followed by spin coated a polymer blends of MDMO-PPV/PCBM in chlorobenzene onto PEDOT:PSS layer. Finally, evaporation of a silver electrode and PET film lamination completed the devices. The typical overall power efficiency of the prototype devices in an active area of 2.6 cm2 was 0.004 % with open-circuit voltage of 1.473 Volt, short-circuit current of 5.84 x 10^-06 Ampere, and maximum power of 2.12 x 10^-06 Watt.

Abstract: Atomic layer deposition (ALD) technique shows superior application in the fabrication of TiO₂ inverse opals (IO), compared with conventional infiltration methods. In the present report, TiO₂ IO structures were infiltrated by ALD method in a continuous-flow and internally developed stop-flow process, respectively. The corresponding optical and optoelectrical properties of TiO₂ IO structures were investigated. The prepared uniform IO structure of 288 nm was used as a photoanode for dye-sensitized solar cells. An efficiency of 2.22% was achieved, which was much higher than that of prepared by conventional solution-infiltration method. It is indicated that ALD method is an effective approach for fabricating TiO₂ IO photoanode.

Abstract: Two-step growth method was used for CuInGaSe₂,(CIGS) absorption layer in this study. The layer was first deposited by thermal evaporator to use indium and gallium sauces at a vacuum of 5 × 10^-6 torr and secondly, the deposited thin film was enclosed in a quartz cartridge for the first selenization. The second selenization process was coated by copper and then annealed again in a furnace. Finding best precursor for thin film solar cells was analyzed by scanning electron microscope (SEM), X-ray diffraction analyzer (XRD) and energy dispersive spectrometer (EDS).

Abstract: The surface inspection of crystalline silicon wafers is of importance in manufacturing processes for solar cells. In this paper, The laser scattering mechanism is designed and manufactured through detailed investigations of the light scattering characteristics. Its parameters are to be optimally selected to obtain effective and featured patterns of laser scattering. The optimal parametric ranges of laser scattering are determined using the mean intensity of laser scattering. As a result of the experimental analysis of laser scattering patterns, two pieces of evidence that are effective for the detection of micro defects are extracted. It is confirmed that the two features are regarded as important information for the detection of defects in crystalline silicon wafers. The usefulness of the designed mechanism and of extracted features is verified through experimental results.

Abstract: CuInSe₂ thin films were prepared under vacuum by conventional evaporation method .The films were deposited at different film thickness (188-577nm) .XRD of as-prepared powder indicated that CuInSe₂ has tetragonal poly crystalline structure with(122) preferred orientation, while XRD of the as-deposited films were of a mixed amorphous- microcrystalline nature. The variation of the calculated lattice parameters at different film thickness were showed. The electrical properties of CuInSe₂ thin films were studied at different film thickness. The dark conductivity of the films was measured as a function of temperature. Two regions were obtained corresponding to two activation energy. The activation energy decreases with increasing the film thickness.

Abstract: We organized a project of solar cells in University of Miyazaki in order to develop the technologies for solar cells. We have four kinds PV module systems, such as hybrid Si Thin film (1 kW), Poly-Si (50 kW), CIS (100 kW) and CPV (14 kW×2). Their total is 179 kW. These take appoximately 5% of total electricity of the university.