Also, the K–I stretching band that appear at 1380 cm1 is shifted to 1395 cm1 due to the capture of K+ through the complexation of the polymer matrix with the iodine salt. This capture of K+ frees the I for migration to regenerate the oxidized dye molecules [22,23]. Iodine ions migration will increase the ionic conductivity and helps overcoming the decrease in Jsc as a result of adding pyridine.