Improving the Power Conversion Efficiency of Organic Solar Cell by Blending with CdSe/ZnS Core-Shell Quantum Dots

摘要

We have blended poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C-61 butyric acid methyl ester (PCBM) with CdSe/ZnS core-shell quantum dots (QDs) as the active layer to produce organic solar cells (OSC). The size of the CdSe/ZnS core-shell QDs was determined to be about 4 nm using transmission electron microscopy. The OSC were characterized by measuring the absorption spectra, current-voltage characteristics, and external quantum efficiency (EQE) spectra. The samples doped with 0.5 wt.% CdSe/ZnS core-shell QDs exhibited higher power conversion efficiency (PCE) than samples doped with other concentrations of QDs. The PCE of the OSC increases from 2.10% to 2.38% due to an increase of the short circuit current density (J (sc)) from 6.00 mA/cm(2) to 6.25 mA/cm(2). The open circuit voltage (V (oc)) was kept constant when comparing OSC that were undoped and doped with 0.5 wt.% CdSe/ZnS core-shell QDs. These CdSe/ZnS core-shell QDs can increase optical absorption as well as provide extra exciton dissociation and additional electric pathways in hybrid OSC.