Continuous roll-to-roll serpentine deposition for high throughput a-Si PV manufacturing

In order to improve further the economies of scale which are inherent in continuous roll-to-roll amorphous silicon alloy solar cell manufacturing processes, the authors 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 roll-to-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, the authors have constructed a single loop serpentine deposition chamber to deposit an a-Si for n-i-p structure solar cells. During the initial process of optimization, the authors have produced single-junction a-Si solar cells with an 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