United Solar Systems Corporation

Gary M Didio

Prem Nath

Kevin R Hoffman

Jon Call

Timothy D Laarman

Kermit Jones

In continuous apparatus for the glow discharge deposition of amorphous silicon alloy solar cells of p-i-n-type configuration in a plurality of interconnected, dedicated deposition chambers, a plasma bar operatively disposed between at least the plasma regions in which the layer pairs of amorphous silicon alloy material defining the major semiconductor junction of the solar cell are deposited. The plasma bar is adapted to initiate a plasma so as to prevent chemically adsorbed contaminants from deleteriously affecting the surface of the first deposited of the layer pair, thereby improving the open circuit voltage of the solar cell. In a similar manner, the plasma bar may also be provided between the layer pairs of amorphous silicon alloy material which combine to define the minor semiconductor junction of the solar cell. Finally, a plasma bar may be disposed between the oxide-based layer of a back reflector for reducing oxygen contamination of the silicon alloy material deposited thereupon.

Interfacial plasma bars for photovoltaic deposition apparatus

An improved gas gate (34) is adapted to operatively interconnect to adjacent chambers in which process gases are introduced for depositing a first layer (16) upon a substrate (11) in a first chamber (28) and different process gases are introduced for depositing a second layer (18) in the second chamber (30) in continuous low pressure glow dicharge deposition process. A plurality of electrodes (60) and grounded shields (62) are positioned in the isolation passageway (92) of gas gate (34). The electrodes (60) have a potential sufficient to create a plasma from any gas molecule escaping from one of the deposition chambers. After the plasma is formed it is attracted to and captured or plated on the shield (62) preventing the gas plasma from landing on the substrate material (11) or passing through the gas gate. The present invention reduces the back diffusion of gases through the gas gate by actively eliminating free gas molecules by ionizing them to form a plasma and capturing the plasma ions in a permanent fashion.

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Highland, MI, United States of America

Gary M Didio