Improvement of Efficiency of Polymer-Zinc Oxide Hybrid Solar Cells Prepared by Rapid Convective Deposition
The aim of this research is to study improvement of power conversion efficiency (PCE) of organic-inorganic hybrid bulk heterostructure solar cell prepared by rapid convective deposition as a function of concentration of zinc oxide additive. The structure of hybrid solar cell used in this research is ITO/ZnO/P3HT:PC70BM:ZnO(nanoparticles)/MoO3/Au. By adding 5 mg/ml of ZnO nanoparticles in the active layer (P3HT:PC70BM), the PCE was increased from 0.46 to 1.09%. In order to reveal the origin of improving efficiency, surface morphology and optical properties of active layers were investigated by atomic force microscopy (AFM) and UV-Visible spectroscopy, respectively. The results clearly indicate that the enhancement of solar cell efficiency results from (i) the proper phase sepharation of electron donor and acceptor in the active layer and (ii) the better absorption of the active layer. This research work introduces an alternative way to improve solar cell efficiency by adding ZnO into active layer.