Investigation of Chemical Bath Deposition of ZnO Nanocrystals Thin Films Using Different ZnNO3 Concentration

In this work, thin films growth at different ZnNO3 concentrations： 0.02 M, 0.03 M and 0.04 M by chemical bath deposition （CBD） as-prepared on glass substrates at 80 ℃ ± 2 ℃. Patterns Diffraction x-ray （DRX） shown peaks 20 = （31.72, 32.769, 34.36, 36.10, 47.44, 56.52, 62.78, 67.84 and 69.02）, at concentration 0.02 M show formation from hydrozincite [Zn5（CO3）2（OH）6]. The optical band gap shifts from 3.8 eV to 3.6 eV. Photoluminescence （PL） spectra show intensity variation of the green emission （GE） may be resulted from variation of the intrinsic defect in ZnO films, such zinc vacancy （Vzn）, oxygen vacancy （Vo）, and interstitial zinc （Zni）, interstitial oxygen （Oi）. The presence of defects in our samples is responsible for the observed broad visible PL bands; this indicates reductions of oxygen vacancies and increase of oxygen interstitials. It could be believed that the presence of defects in samples is responsible for the observed broad visible PL band. The concentration increased the visible defect luminescen