Eliminating the Need for Handling Individual Sub-Cells for Small Appliance PV Modules with Voltage Demands Above 12V

There is a high demand for small photovoltaic (PV) modules that can provide 12V or more to operate electronic devices with low power consumption, such as parking meters, street signs, and remote Internet of Things (IoT). However, state-of-the-art PV modules either require several step-up converters to achieve the necessary voltage or are put together from small sub-cells, requiring a significant handling and interconnection overhead during manufacturing. The technology described in this work allows to interconnect small rear contact solar cells before their segregation, eliminating the need for the handling and interconnection of individual sub-cells. This is demonstrated by creating modules of thirty-six sub-cells from a single monolithic wafer. The resulting modules showed an open circuit voltage of over 24V and voltage at maximum power point of just under 20V while reaching a power of about 4.4W. The novel AI-foil interconnection technique utilizes laser welding and Aluminum (AI) to substitute environmentally harmful materials such as solder including lead and solder-forming fluxes. Furthermore, it significantly reduces the use of silver, as large segments of the electrodes such as busbars or soldering pads are no longer necessary.