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CuInSe2/CdS thin film solar cells by r.f. sputtering
No full textCuInSe2/CdS thin film solar cells were prepared by rf sputtering on an Al-covered glass substrate. The Al layer, deposited using an electron gun, is crystalline with an average grain size of 100μ. The Mo bottom contact, the CuInSe2 and CdS films were sputtered in sequence in the same sputtering chamber without breaking the vacuum. The CdS film deposited at substrate temperature of 200°C has a resistivity of ≈1 Ωcm due to small amount of H added during the deposition which increases the S vacancies in the film. CuInSe2/CdS sputtered solar cells have an efficiency of ≈4-5%. A higher efficiency can be obtained by improving the structural and electro-optical properties of CuInSe2 thin films
Large Crystalline Grain CdTe Thin Films for Photovoltaic Application
No full textA simple new method suitable to grow large crystalline grain CdTe thin films on glass substrates has been developed. CdTe films which exhibit a grain size larger than 20 μm have been obtained. The films are p-type with a resistivity of about 100 Ωcm. Backwall CdTe/CdS thin film solar cells with an efficiency above 9% have been prepared
Zinc Cadmium Sulphide (Zn0.15Cd0.85S) thin-films by rf sputtering in an Ar-H2 atmosphere
No full textFilms of the title compound were prepared by radio-frequency sputtering from a (Zn,Cd)S target in pure Ar and Ar-H atoms. At a substrate temperature of 200°, Zn0.15Cd0.85S films grown in an Ar-H atmosphere exhibit a resistivity of ≈3 orders of magnitude lower than that of films grown in pure Ar. This is attributed to the formation of S vacancies by H reaction with a small number of the S atoms during the film deposition. The film grown in the Ar-H atmosphere exhibits a transparency of almost 100% when corrected for reflection loss for wavelengths longer than that of the absorption edge; the forbidden gap obtained from the absorption spectrum is ≈ 2.53 eV. The films prepared by sputtering in an Ar-H atmosphere are suitable for windows in CuInSe2/(Zn,Cd)S solar cells
Doped transparent conducting oxides suitable for the fabrication of high efficiency thin film solar cells
No full textDivergent sequential reactions of alpha,beta-(2-aminophenyl)-alpha,beta-ynones with nitrogen nucleophiles
No full textbeta-(2-Aminophenyl)-alpha,beta-ynones readily react with nitrogen nucleophiles to give three major types of products, depending on reaction conditions and variation in the nucleophiles. The reaction may lead to simple 1,2-nucleophilic adducts or, at higher temperatures, to a divergent sequential cyclisation giving rise to 2-aryl-4-aminoquinolines by reaction with amines, or to substituted 2-aryl or 2-alkyl-4-alkylidene quinazolines by reaction with amidines. The latter could also be synthesised by reaction of beta-(2-aminophenyl)-alpha,beta-ynones with iminochlorides
Why CuInGaSe2 and CdTe polycrystalline thin film solar cells are more efficient than the corresponding single crystal?
No full textRecently, very high conversion efficiencies in thin film polycrystalline solar cells have been reported. In particular it was reached an efficiency record both for CuInGaSe2 (CIGS) and CdTe that are 19.2% and 16.5% respectively. We will briefly describe the technological methods used to fabricate these thin film solar cells. Besides, we will try to explain the reason why thin film polycrystalline devices can achieve conversion efficiency comparable with those shown by single crystal solar cells (mono-Si or poly-Si). We will take into consideration the tricks present in both the methods that allow to make the CIGS/CdS and CdTe/CdS thin film solar cells with excellent performances. We will show also, that these technologies are ripe for an "inline" industrial production and this makes thin film solar cells the best candidates for the large scale utilisation of photovoltaic energy conversion. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei
Environmental implications of the surfactants effect on the photochemistry of(substituted) 4-chlorophenols in water
No full textLow resistivity CdS thin films grown by r.f. sputtering in an Ar-H2 atmosphere
No full textLow resistivity (10÷1 - Ω cm) CdS thin films were deposited onto glass substrates by r.f. sputtering in an Ar-H2 atmosphere at substrate temperatures in the range 100–200 °C. These films are highly transparent in the wavelength region between 1.6 μm and the absorption edge of CdS (0.52 μm) and are therefore suitable to be used as windows in heterojunction solar cells such as CuInSe2/CdS or CdTe/CdS. Hall mobilities of such films on glass substrates are of the order of 10–20 V/cm2 s
Thin Film CuInSe2/CdS Solar Cells by R.F. Sputtering
No full textThin film CuInSe2/ZnCdS solar cells have been prepared by depositing all layers which compose the device by R.F. sputtering. While the ZnCdS window layer exhibits the right characteristics which are required for the preparation of high efficiency cells, the R.F. sputtering CuInSe2 film, even though it has been prepared by the deposition in sequence of an In-rich layer on top a Cu-rich layer, requires still further research in order to reach the high quality required for high efficiency devices. All sputtered CuInSe2/ZnCdS solar cells have so far exhibited an efficiency of about 6%
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