Solution processing route to high efficiency CuIn(S,Se)₂ solar cells

Inorganic semiconductors have properties that are notoriously difficult to control due to the deleterious impact of crystalline imperfections, and this is especially so in solar cells. In this work, it is demonstrated that materials grown using wet chemistry processes for the preparation of nanocristalline precursors can achieve the same performance as the best state of the art, namely conversion efficiencies above 11% with CuInS₂. Interestingly, due to the growth process, the active material inherit a porous morphology that is shown to play a part in the performance and functionality of the active material. The new device morphology leads to a device operation closer to that of nanoscale organic interpenetrated solar cells or dye sensitized solar cells than to those of standard polycrystalline ones.