The effect of pH on ZnO hydrothermal growth on PES flexible substrates

The effect of pH value and a ZnO buffer layer on structural properties and morphology of ZnO nanostructures was investigated in this work. The nanostructures were fabricated on polyethersulfone (PES) flexible substrates with and without a ZnO buffer layer using a hydrothermal synthesis process, and the pH value was varied from 6.65 to 8.5. The ZnO buffer layer was deposited onto the substrates using atomic layer deposition (ALD). X-ray diffraction and scanning electron microscopy were used to characterize the samples. Hydrothermally grown ZnO deposited onto a buffer-ZnO/PES substrate at a pH of 7.5 was found to exhibit the optimal structural properties.