High-performance flexible transparent p-CuI film by optimized solid iodization

High-performance flexible transparent p-CuI films were prepared on polycarbonate substrates at room temperature by combining solid iodization and vacuum thermal evaporation. The structural analysis shows that as prepared CuI films are polycrystalline with zinc blende structure, exhibiting highly preferred oriented (1 1 1) plane. Atomic force microscope shows homogeneous surface morphology with no fissure or exfoliation. X-ray photoelectron spectra indicate that the valence state of copper is Cu+ after being completely iodinated and the calculated value of [I]/[Cu] increases as iodination time increase. The improvement of electrical performance is inseparable from the relative content of excess iodine. Moreover, the flexible p-CuI films exhibit a high average transmittance of 87.1% in the visible region with excellent conductivity of 31.7 S/cm, which shows superior performance than the other rigid p-type transparent conductors prepared at high temperatures. In particular, flexible p-CuI films also display excellent durability and flexibility in the tests of the radius of curvature and bending cycle. These results prove that the as-prepared p-CuI films have great potential in flexible and wearable electronics.

Automated summary

High-performance flexible transparent p-CuI films were successfully prepared on polycarbonate substrates, exhibiting polycrystalline with zinc blende structure and highly preferred oriented (1 1 1) plane. These films show excellent electrical performance with high average transmittance and conductivity, surpassing rigid p-type transparent conductors prepared at high temperatures. Additionally, the flexible p-CuI films demonstrate superior durability and flexibility, making them promising for flexible and wearable electronics.