摘要 |
A continuous deposition process and apparatus for depositing semiconductor layers containing cadmium, tellurium or sulfur as a principal constituent on transparent substrates to form photovoltaic devices as the substrates are continuously conveyed through the deposition apparatus is described. The film deposition process for a photovoltaic device having an n-type window layer and three p-type absorber layers in contiguous contact is carried out by a modular continuous deposition apparatus which has a plurality of processing stations connected in series for depositing successive layers of semiconductor films onto continuously conveying substrates. The fabrication starts by providing an optically transparent substrate coated with a transparent conductive oxide layer, onto which an n-type window layer formed of CdS or CdZnS is sputter deposited. After the window layer is deposited, a first absorber layer is deposited thereon by sputter deposition. Thereafter, a second absorber layer formed of CdTe is deposited onto the first absorber layer by a novel vapor deposition process in which the CdTe film forming vapor is generated by sublimation of a CdTe source material. After the second absorber layer is deposited, a third absorber layer formed of CdHgTe is deposited thereon by sputter deposition. The substrates are continuously conveyed through the modular continuous deposition apparatus as successive layers of semiconductor films are deposited thereon.
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