| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1553556 | Superlattices and Microstructures | 2014 | 6 Pages |
•We investigated the importance of pH and annealing temperature on the crystallinity of nanocrystals.•The band gap has been found to lie in the range of 3.62–3.72 eV.•Achieved maximum power conversion efficiency of 2.05% for the nanocrystals synthesized at pH = 9.
ZnO nanocrystals have been synthesized via simple precipitation method at different pH values. The synthesized nanocrystals are annealed at three different temperatures such as 400, 500 and 600 °C respectively. The X-ray diffraction pattern shows that synthesized ZnO nanocrystals are of hexagonal structure and the grain size was found to be in the range of 30–60 nm. The results also indicated that the crystallinity of the nanocrystals improved with increase of pH values and annealing temperature. Scanning electron microscopic image shows that the surface morphology improves with increase of pH values. Optical absorption studies show that the band gap has been found to lie in the range of 3.62–3.72 eV depending on pH suggesting the formation of ZnO nanocrystals. Dye sensitized solar cells prepared using ZnO nanocrystals synthesized at pH = 9 exhibits an enhanced short-circuit current density of 5.06 mA/cm2, open-circuit photo voltage of 0.61 V, fill factor of 0.65, and overall power conversion efficiency of 2.05%.
