Preparation and properties of CdTe polycrystalline films for solar cells

Abstract

The structure and characteristics of CdTe thin films are closely dependent on the whole deposition process in close-space sublimation (CSS). The physical mechanism of CSS was analyzed and the temperature distribution in CSS system was measured, and the influences of the increasing-temperature process and pressure on the preliminary nucleus creation were studied. The results indicate: the samples deposited at different pressures have a cubical structure of CdTe and the diffraction peaks of CdS and SnO₂: F. As the atmosphere pressure increases, the crystal size of CdTe decreases, the rate of the transparency of the thin film decreases and the absorption side moves towards the short-wave direction. After a 4-minute depositing process with a substrate temperature of 500°C and a source temperature of 620°C, the polycrystalline thin films can be made, so the production of high-quality integrated cell with SnO₂: F/CdS/CdTe/Au structure is hopeful.

Keywords

CdTe solar cell / close-spaced sublimation / polycrystalline thin film / depositing process

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