Optimization of the in situ series connection of amorphous silicon solar modules on glass and foil substrates

Thin film solar cell technology allows for integrated monolithic series connection. During manufacturing of the cells, patterning steps in between the layer depositions form cell stripes and form the monolithic series connection between the front contact of one cell and the back contact of the adjacent one. The in situ series connection (ISSC) technology is not patterning in between the layer depositions but during the depositions. The patterning during layer deposition offers a couple of advantages over common laser scribing techniques. The in situ patterning does not break the vacuum or workflow to establish the monolithic series connection. The non‐thermal patterning enables the use of any flexible or rigid substrate like glass plates or polyethylene naphthalate (PEN) foil. We present the optimization of the wire pattering for plasma enhanced chemical vapor deposition and sputtering of highly conductive front contact material with three times improved shunt protection for an optimized production yield. Evaluating the interconnection losses of the ISSC projects interconnection losses down to 7% with optimized patterning. First amorphous silicon (aSi)‐based ISSC modules exhibit a total interconnection loss F = 15% on PEN foil. Moreover, for the first time we report on the successful implementation of the ISSC of aSi cells on rigid glass substrates.