Abstract
ZnO nanorods have been synthesized on glass substrate by low-cost two step chemical bath deposition (CBD) method at low temperature. The ZnO seed layers have been coated on glass substrate by RF magnetron techniques with power 150 watt for 15 min. The influence of different growth time on the optical properties, energy band gap, Raman spectra and surface morphology of ZnO nanorods are investigated. The growth time are (0.5, 1, 2, 3, 4 and 5) h. The double beam UV visible (UV-5000), Raman Spectroscopy and field emission scanning electron microscopy have been used to characterize the optical properties (absorption and transmission), energy band gap, Raman spectra, surface morphology, diameter, distribution and homogeneity of produced ZnO nanorods. The results found that the growth time have significant effect on the optical properties, energy band gap, Raman modes, aligned, surface morphology, diameter, ZnO distribution and density. And It is observed that the absorbance of the growth times 4 and 5 h are higher than the other growth times of ZnO nanorods, which showed the good crystallinity of the other samples. The transmittance decreases sharply near UV region at wavelength around 385 nm due to the optical band gap absorption. The obtained energy band gap of ZnO nanorods decreases with increase in the growth time from 3.25 eV to 3.18 eV. From result, it was investigated that the growth time caused the average crystalline size increases and decreases defects causing the energy band gap decreased. From Raman spectra, it observed that the dominant and sharp peaks at approximately 100 cm(-1) and 437 cm-1 for the ZnO nanorods grown of 4 h and 5 h as a growth times, which are corresponds to the intrinsic characteristics of the Raman active E-2(low) and E-2(high) modes of the hexagonal wurtzite ZnO, respectivlyAlso FESEM results shows that the growth time has a good playing role on the nanostructure growth orientation of the ZnO nanorods.