Module interconnection for the three-terminal heterojunction bipolar transistor solar cell

In common multijunction solar cells the subcells are connected in series. In this way, achieving a high voltage at module level is straightforward. However, calculations have proven that the annual energy efficiency limit is higher for independently connected subcells, because they are more tolerant to spectral variations throughout the year. We have recently proposed a three-terminal heterojunction bipolar transistor solar cell (HBTSC) with the maximum limiting efficiency of a dual-junction solar cell, but without the need for a tunnel junction and with only three crucial semiconductor layers. In this work, we present the implementation of a two-terminal module prototype including five HBTSCs which provides a high-voltage power output.