The effect of annealing on the energy gap of Polyimide (PI) and Polyethylene terephthalate (PET) Polymers. Iraqi Journal of Science [Internet]. 2025 Feb. 8 [cited 2025 Feb. 8];46(1):141-4. Available from: https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/15007