||In this study, zinc oxide (ZnO) nanotip array will be grown on ZnO nucleation layer by aqueous solution deposition (ASD). Characteristic of the ZnO nanotip array will be investigated. We will discuss the lattice mismatch that affect the crystallization of ZnO nucleation layer and morphology of ZnO nanotip array. The PL analysis of ZnO nanotip array shows the typical emissions of narrow exciton related UV band peak at 375 nm and broad defect related green–yellow (550~650 nm) bands. The green-yellow emission (550~650 nm) is likely due to O vacancies and the emission is improved after N2O annealing at 300 oC. Under UV light illumination, the electron-hole pairs are generated in ZnO by the photoexcitation and then the pairs diffuse to the surface. Holes could enhance the decomposition of ammonia and hence the concentration of OH- will be increased. The growth rate of ZnO nanotip array could be enhanced because of the ultraviolet light illumination. ZnO nanotip array with rough surface decreases reflection, so we use ZnO nanotip array as an anti-reflection layer. After coating ZnO nanotip array on solar cell, the efficiency of solar cell is enhanced.|
The morphology is observed by field emission scanning electron microscope (FE-SEM). The physical properties are characterized by X-ray diffraction (XRD). The optical properties are measured by Micro-photoluminescence (Micro-PL). The performance of the cells is measured by a semiconductor device analyzer. In our results, we grow the high performance of ZnO nanotip array on solar cell to increase the efficiency. The short-circuit current is increased from 40.49 to 44.01 mA, and the efficiency is increased from 13.388 to 14.4%.
Keywords: aqueous solution deposition (ASD), zinc oxide (ZnO), nanotip, moth eye principle, anti-reflection, solar cell