Enhanced organic solar cells performance enabled by complementary absorption using aluminum phthalocyanine chloride

Loading a suitable guest molecule exhibiting unique features into a binary active layer has been considered as an effective tool for enhancing the solar cells performance. In our bit to enhance the performance of the binary solar cells based on poly (3-hexyl thiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PC61BM), the possibility of incorporating aluminum phthalocyanine chloride (AlPcCl) into the active layer is investigated. The P3HT: AlPcCl: PC61BM shows intercalated nanostructure. By loading AlPcCl, the interplanar spacing increases, whereas the crystallite size decreases. The molecular bonding of P3HT, AlPcCl, PC61BM and their composites is investigated in terms of Fourier transforms infrared spectroscopy. In addition, the surface morphology and topography are investigated using field emission scanning and atomic force microscopes. Analysis of the absorbance spectra of the active layer reveals that the introduction of AlPcCl enhances the intensity of absorption and broadens its range. More interestingly, the reference solar cell based on P3HT: PC61BM active layer delivers a photoelectrical conversion efficiency (PCE) of 3.16%. By loading AlPcCl, the PCE value is promoted to 4.46%. Based on structural, optical and photoelectrical properties, this behavior is mainly ascribed to the promotion of the photocurrent of the cells which is supported with the external quantum efficiency measurements.