Abstract:
The aim of this study is to investigate the effect of zinc oxide and copper oxide concentration on polymer solar cell performance.
A layer of polymer with concentration of 0.2 ml gram/ml was deposited on the ITO glass. The anode was made from aluminum while ITO represent the Cathode ,I n this work ZnO solar cells fabricated from polymer, with different ZnO concentrations ranged from (0.3 to 0.25) mg/mL were prepared. The performance of these cells show increase in the efficiency when the concentration of ZnO increase. This agrees with the theoretical relations.
However some results show efficiency increase, when the concentration decrease. This can be explained by a mechanism similar to that of Mott insulator, due to the change of the position of the Fermi level.
Other samples were formed by changing ZnO by CuO in polymer solar cells, with different CuO concentrations ranged from (0.3 to 0.25) mg/mL. It was found that increasing CuO concentration increases efficiency. This can be explained on the basis of the relation between current and concentration of CuO It is found that there is a sudden increase in the efficiency of the cell at concentrations of (0.28 and 0.25) this is explained by the same mechanism of Mott Insulator of super conductivity. It assumes the existence of narrow energy band in the energy gap; the shift of Fermi Level affects the efficiency.
It was found that the copper oxide energy gap is less than that of the zinc oxide.
Also the absorption coefficient and efficiency of copper oxide are more than that of zinc oxide, this agrees with physical theories and previous studies.
