Optical Modeling of Copper Oxide Nanoleaves Synthesized by Hot Water Treatment

In this study, optical absorption properties of copper oxide (II) (CuO) nanoleaf structures grown by hot water treatment (HWT) method were investigated by a numerical simulation method and were compared to experimental results. For this purpose, 3D CuO nanoleaves (NLs) were synthesized by HWT, which simply involved immersing a Cu plate or thin film sample in hot deionized (DI) water. For comparison, we prepared a conventional CuO thin film by thermal oxidation of copper film at about 300 degrees C. Optical transmission and reflection were measured by UV/Vis/NIR (ultraviolet-visible-near-infrared) spectrophotometer, which were used to calculate optical absorptance. Numerical simulation was performed with finite difference time domain (FDTD) simulation software. Reflectance, transmittance, and absorptance of CuO NLs of different roughness (i.e. CuO NLs layer thickness) were calculated through FDTD method and compared with the experimental results. FDTD simulations predict that nanoleaves morphology enhances light absorption by improving diffuse light scattering and light trapping properties which effectively increases the optical path length without using more material as compared to the thin film structure. This can be useful for developing thinner nanostructured optoelectronic devices with low cost and high efficiency.