ENHANCING THE EFFICIENCY OF FTO/ZnO NANORODS/P3HT/Ag HYBRID SOLAR CELLS BY SENSITIZING CdS QUANTUM DOTS

Abstract

An improvement in the performance of the inverted organic solar cells based on zinc oxide/ poly(3-hexylthiophene)(ZnO/P3HT) is modified by deposited cadmium sulfide quantum dots (CdS QDs) were prepared via successive ionic-layer adsorption and reaction (SILAR) on ZnO nanorods (ZNRs). The size of CdS QDs on the ZNRs surface were controlled when the QDs were prepared from varied concentration of precursor solutions (0.01,0.05 and 0.10) M using 5 SILAR cycles of deposition for 5 min in each solution. The results of photocurrent-voltage (I-V) measurement showed that CdS modification first can improve all photovoltaic parameters and increase the power conversion efficiency of the hybrid solar cells and then decreased as concentration of precursor solutions increased. A maximum power conversion efficiency (PCE) of 0.52% was obtained for the CdS QDs at the concentration 0.05 M, which was increased almost three times compared with the solar cell without using CdS QDs. Open circuit voltage (Voc) and short circuit current (Jsc) improved with increasing concentration of precursor solutions up on 0.05 M, which can reduce charge carrier recombination in the interface between ZNRs and P3HT after deposit CdS QDs.