Organic donor/acceptor heterojunction photovoltaic devices based on zinc phthalocyanine and a liquid crystalline perylene diimide

An organic photovoltaic cell was fabricated, with the configuration ITO/zinc phthalocyanine (ZnPc)/N,N′-diheptyl-3,4,9,10-perylenebiscarboximide (PTCDI-C7) (PTCDI)/Ga:In. PTCDI is a liquid crystal and acts as an electron acceptor organic material while ZnPc corresponds to a donor. The cell performance under illumination was examined with different organic layer thickness. A cell incorporating 25 nm thick organic layers showed a short circuit photocurrent (ISC) of 1.6 mA/cm2, an open circuit photovoltage (VOC) of 0.6 V, and a fill factor (FF) of 0.4 with white Xe light illumination (wavelength ⩾400 nm) with an intensity of 100 mW/cm2.