Upgrading the silicon IBC to the 40% efficiency

A new approach of a tandem silicon technology is presented. That is based on improving a classical IBC structure in which top and bottom cells are jointed on. The electrical connection of this tandem device is not the classical series connected but the voltage matched approach. The final device would be of a maximum efficiency of 39.5% but it is more tolerant to light spectrum, degradation and not optimum materials than conventional series connected and using well known materials for each level an 30 to 32% efficiency level sounds possible.