Polymer photovoltaic cells by using manganese phthalocyanine derivative

Abstract

A novel near-infrared absorbing manganese phthalocyanine bisphenol A epoxy derivative (MnPc-DGEBPA) was synthesized and characterized by infrared, UV–Vis and fluorescence spectra. The absorption spectrum of the derivative exhibited a Q-band in the near-infrared region and its fluorescence quantum yield reached 0.36 in N, N-dimethylformamide. MnPc-DGEBPA has high solubility and good film forming ability as well. The MnPc-DGEBPA films with a planar electrode were prepared by the dip-coating process using 2, 9, 16, 23-tetra-amino manganese phthalocyanine (TAMnPc) as a solidifying reagent. The current–voltage characteristics of the films were measured and photoconductivity was increased by an order of magnitude compared with dark conductivity, which indicates that MnPc-DGEBPA films have good photoelectric response. Schottky-type and pn-junction-type photovoltaic cells with ITO/MnPc-DGEBPA/Al and ITO/MnPc-DGEBPA/C60/Al structures were achieved by spin coating (using TAMnPc as a solidifying reagent) and vacuum evaporation. The open-circuit voltage (Voc) and short-circuit current density (Jsc) of the Schottky device were 0.6 V and 4.7 nA cm−2, while Voc and Jsc of the pn-junction device were 0.14 V and 0.45 µA cm−2, respectively. The photocurrent efficiency of the pn-junction cell was about 0.1%.