Effect of CdSe nanoparticles incorporation on the performance of P3OT organic photovoltaic cells

Photoluminescence and photovoltaic properties of P3OT:%CdSe nanocomposite films are investigated as a function of the mass concentration (wt%) of the CdSe nanoparticles (NPs) incorporated in the films. The incorporation of CdSe NPs produces a quenching of the photoluminescence and improves the performance of the nanocomposite solar cells. These effects are explained in terms of exciton dissociation and charge separation occurring at P3OT/CdSe interfaces within the Förster formalism, involving non-radiative energy transfer from the donor (P3OT) to the acceptor (CdSe NPs). An exciton quenching rate constant of 1.4×10−10 cm3 s−1 is determined using the Stern–Volmer equation. In addition, scanning electron microscopy (SEM) images reveal that surface morphology is changed by CdSe NPs incorporation, in agreement with FTIR spectra. The current density–voltage (J–V) characteristics of ITO/P3OT:%CdSe/Al photovoltaic cells performed for different CdSe concentrations are also reported and indicate a significant improvement of the photovoltaic parameters cells, particularly, the conversion efficiency becomes 20 times greater than that of the cell based on pure polymer.