Efficient and stable solar cell by interfacial film formation

The development of a new efficient and stable semiconductor-liquid junction solar cell is reported. The n -CuInSe 2 /I 2 -I − -Cu + -HI/C cell utilizes relatively inexpensive, non-toxic components and requires less stringent sealing which makes this cell a more feasible candidate for energy conversion device applications than its predecessors 1–3 . Initial output power measurements have already yielded a conversion efficiency of 9.5% under AM1 (Air Mass 1) conditions. After passage of 70,000 C cm −2 the cell continues to deliver virtually unchanged photocurrents at maximum power point. The performance is based on the in situ formation of an interfacial film that is stable in the operational range of the solar cell.