Preparation of Polyimide/Zinc Oxide Nanocomposite Films via an Ion-Exchange Technique and Their Photoluminescence Properties

Figure 4

XPS spectra for the Zn 2p and O 1s core levels of (a, b) the Zn²⁺-doped film and (c, d) the PI composite film after thermal treatment at 350°C for 7 h.

(a)

(b)

(c)

(d)