CuI p -type thin films for highly transparent thermoelectric p-n modules

Developments in thermoelectric (TE) transparent p -type materials are scarce and do not follow the trend of the corresponding n -type materials – a limitation of the current transparent thermoelectric devices. P -type thermoelectric thin films of CuI have been developed by three different methods in order to maximise optical transparency (>70% in the visible range), electrical (σ = 1.1 × 10 4 Sm −1 ) and thermoelectric properties (ZT = 0.22 at 300 K). These have been applied in the first planar fully transparent p-n type TE modules where gallium-doped zinc oxide (GZO) thin films were used as the n -type element and indium thin oxide (ITO) thin films as electrodes. A thorough study of power output in single elements and p - n modules electrically connected in series and thermally connected in parallel is inclosed. This configuration allows for a whole range of highly transparent thermoelectric applications.