Fabrication and optical property of nano-sized cupric oxide films

Thin nanocrystalline Cu films are deposited on a glass substrate using an improved electroless plating technique and Cu films oxidized using heat oxidation technology, Nanocrystalline Cupric Oxide (CuO) films were fabricated on unetched glass substrate. The process of Cu films oxidized and crystalline structure and grains size were investigated by XRD, FTIR and XPS. The surface morphologies of CuO films with different thickness were characterized by FESEM. Experimental results show that nanocrystalline Cu films were directly oxidized to form nanocrystalline CuO films which have nano-nano structure at 350°C for 1 h. With the thickness of CuO films increasing from 54 nm to 113 nm, the average grains size increases from 12 nm to 23 nm, and the agglomerates size increases from 30~50 nm to 60~100 nm, and the optical transmittance ratio decreases from 74.7% to 65.17%, and the range of band gaps is from 2.83 eV to 2.94 eV.