Effect of growth time on ZnO thin films prepared by low temperature chemical bath deposition on PS substrate

ZnO thin films were successfully synthesized on a porous silicon (PS) substrate by chemical bath deposition method. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and photoluminescence (PL) analyses were carried out to investigate the effect of growth duration (3, 4, 5, and 6 h) on the optical and structural properties of the aligned ZnO nanorods. The small FWHM and stronger diffraction intensity of growth times of 5 h mean the better crystal quality of ZnO thin films compared to others. The grain size of the ZnO thin films gradually increased with increased the growth time. The FESEM images show that the thickness of ZnO thin films increased with increase of the growth time. Photoluminescence measurements showed that there was a sharp and highly intense UV emission peak when growth time was 5 h. The structural and optical investigations revealed that the ZnO thin films grown on the PS substrate with growth time of 5 h had high structural and optical quality.