CONTINUOUS ROLL-TO-ROLL SERPENTINE DEPOSITION FOR HIGH THROUGHPUT a-Si PV MANUFACTURING

In order to further improve the economies of scale which are inherent in ECD’s continuous roil-to-roll amorphous silicon alloy solar cell manufacturing process, we have developed a concept for a serpentine web plasma CVD deposition process to maximize throughput while keeping the size of the deposition chambers small. When this technique is incorporated into a continuous rollto-roll PV manufacturing process, it will maximize the throughput for a high volume production plant, reduce the machine cost, improve gas utilization, reduce power consumption, and improve the solar cell stability. To demonstrate the serpentine web deposition concept, we have constructed a single loop serpentine deposition chamber to deposit a-Si for n-i-p structure solar cells. During the initial process of optimization, we have produced single-junction a-Si solar cells with 8.6% efficiency, and triple-junction a-Si solar cells with a 9.5% initial efficiency, where the top cell intrinsic layer was deposited in the serpentine deposition chamber.