The KIS project aim was to develop new intelligent c-Si cells through innovative production processes at low costs. This was to be achieved by the inclusion of integrated circuits in the actual PV wafer thus facilitating several new applications and designs providing cost effectiveness, intelligence, cell safety against hot spots, stability, and less load and ohmic losses. The KIS cells also provide higher yearly kWh yield compared to traditional high efficiency cells.

The inspiration for the KIS project was the fact that, although PV cells are based on semiconductor material known to be used for the integrated circuit industry, state-of-the-art is that the solar cell has got only one single semiconductor component, namely the emitter diode forming the pn-junction of the cell. So far, all attempts made to introduce new additional semiconductor components into the solar cell wafer have failed. The technological barrier for this has been the lack of alternatives to the extremely expensive Photoresist masking technique and thus the lack of cost-effective technologies for achieving the integration of IC components inside the solar wafer. However, with the KIS project, we have actually managed to integrate new additional semiconductor components in the solar wafer without using Photoresist and without compromising the production costs by combining new designs and new technologies.

Other outcomes from the KIS project are cost benefits from: (1) very large wafer area (2) enabling use of very low-cost Silicon (3) Low current, higher cell efficiency and elimination of the metal grid (4) higher yearly kWh yield by integrated bypass diodes (5) eliminating hot-spot risks and fire hazards and (6) reducing costs of installation of modules. The large area KIS wafer designs are expected to considerably reduce both the Silicon costs, the wafer production costs, the cell production costs, and the module production costs. Further important economic benefits were achieved by the system energy harvesting gains. By introducing a built-in bypass diode for every single cell unit, the new KIS cell modules are expected to provide 5-35% higher yearly kWh/m2 yields than modules based on standard PV cells. Furthermore, the resulting small currents from the small cells could also reduce the use of metal grids on the cell surface, bringing a twofold benefit, higher efficiency and less use of expensive silver pastes. In total the KIS design and production technologies are assumed to halve the material and production costs for solar cells.

Project partners: Aarhus University – Institute of Physics