Self-Assembly of Densely Packed ZnO Nanorods Grown Chemically on Porous Silicon Substrate

Self-assembly of densely packed ZnO nanorods were grown on Porous Silicon (PS) substrate by low-temperature chemical bath deposition. The structural and optical properties of the obtained ZnO nanostructures on PS substrate were systematically studied. The strong and sharp (002) peak compared with other peaks in the X-Ray Diffraction (XRD) indicated thatZnO nanorods formed with superior orientation toward the (002) plan.In addition, the small crystallite size and low compressive strain revealed that the self-assembly of densely packed ZnO nanorods had good crystallinity. Field-Emission Scanning Electron Microscopy (FESEM) indicated that the self-assembly of densely packed ZnO nanorods occurred on the surface, inside the pores and on the pore walls of the PS substrate. FESEM images indicated that the average diameter and length of the ZnO nanorods were 150 and 500 nm, respectively. Photoluminescence spectra (PL) exhibited a strong, sharp UV emission peak at 369 nm.