High efficiency cadmium sulfide (CdS)/cadmium telluride (CdTe) solar cells have been developed using ultrathin CdS films having a thickness of 50 nm. CdS films deposited on indium tin oxide (ITO)/#1737 glass substrates by the metal organic chemical vapor deposition technique, and CdTe films subsequently deposited by the close-spaced sublimation technique were used for the fabrication of CdS/CdTe solar cells. A photovoltaic conversion efficiency of 16.0% under Air Mass (AM) 1.5 conditions has been measured by the Japan Quality Assurance Organization.

No abstract

Cadmium sulfide (CdS) thin films are the most commonly used window materials for high efficient cadmium telluride (CdTe) and chalcopyrite polycrystalline thin-film photovoltaic devices. High efficient CdS/CdTe solar cells with thin CdS films have been developed using ultrathin CdS films with a thickness of less than 0.1 µm. CdS films were deposited on transparent conductive oxide (TCO)/glass substrates by the metal organic chemical vapor deposition (MOCVD) technique. CdTe films were subsequently deposited by the close-spaced sublimation (CSS) technique. The screen printing and sintering method fabricated carbon and silver electrodes. Cell performance depends primarily on the electrical and optical properties of CdS films. Therefore we started to develop higher-quality CdS films and found clear differences between high- and low-quality CdS films from the analyses of scanning electron microscope (SEM), atomic force microscope (AFM), secondary ion mass spectroscopy (SIMS), thermal desorption spectrometry (TDS) and Fourier transforms-infrared spectrometry (FT-IR) measurements. As a result of controlling the quality of CdS films, a photovoltaic conversion efficiency of 10.5% has been achieved for size of 1376 cm2 of the solar cells under the Air Mass (AM) 1.5 conditions of the Japan Quality Assurance Organization.

No abstract

Highly transparent, low‐resistance SnO2:F films suitable as a substrate material for thin film CdS/CdTe solar cells have been developed on 10 × 10 cm glass substrates by an ultrasonic spray pyrolysis (pyrosol) technique using dimethyltin dichloride (DMTDC) as a tin source. DMTDC, NH4F , and HF, all dissolved in water, served as the source solution. An ultrasonic vibrator operated at 1.5 MHz produced a fine spray of the source solution. It was transported, using air as a carrier gas, to moving glass plates in a belt furnace maintained at 530°C. A very high growth rate of nearly 100 Å/s was realized in this process with good homogenity, high transparency, and low resistivity. Films with a sheet resistance of less than 10 Ω/□ have been routinely prepared and their preparation technology has been well established. A proper nozzle design and exhaust system to remove the spent gases determines the technology of obtaining spot and cloud free homogeneous films in the belt furnace. A film of 5000 Å thickness exhibited the lowest electrical resistivity, of 3.9×10−4 normalΩ normalcm , a mobility value of 38 cm2 V−1 s−1 , and a donor concentration of 4.16×1020 cm−3 . Films of 5000–6000 Å thickness having an average transmittance of nearly 85% in the visible range and a sheet resistance of around 8 Ω/□ were used as transparent conducting oxide film substrates to fabricate thin film CdS/CdTe solar cells. A solar energy conversion efficiency of over 14% was achieved. © 1999 The Electrochemical Society. All rights reserved.

No abstract

No abstract

A Pyrosol Technique to Deposit Highly Transparent, Low-Resistance SnO 2 :F Thin Films from Dimethyltin Dichloride.-SnO 2 :F films suitable as substrate material for CdS/CdTe solar cells are prepared by an ultrasonic spray pyrolysis (pyrosol) technique using Me 2 SnCl 2 as tin source. Me 2 SnCl 2 , NH 4 F, and HF dissolved in water serves as source solution. High quality films with resistivity values as low as 3.9·10 −4 Ω cm and an average transmittance of about 85% at 550 nm and 500Å thickness are obtained. -(OMURA, K.; VELUCHAMY, P.; TSUJI, M.; NISHIO, T.; MUROZONO, M.; J. Electrochem. Soc. 146 (1999Soc. 146 ( ) 6, 2113Soc. 146 ( -2116 Photovoltaic Res. Dev. Cent.,