Piezoelectric Enhancement of Hybrid Organic/Inorganic Photovoltaic Device

Solar cells are produced using solution processing that combine ZnO nanorods with the conjugated polymer poly(3-hexylthiophene) (P3HT). ZnO nanorods have an average length and diameter of 2.7 μm and 81 nm, and are well coated with P3HT. The solar cells have a power conversion efficiency of 1.24 %, which increases to 1.78 % when 10 kHz acoustic vibrations are applied to the device at 75 dB using a loudspeaker. Transient absorption studies demonstrate that the efficiency increase originates from a decrease in the non-geminate recombination rate in the system. It is proposed that electric fields at the ZnO:P3HT interface arising from the piezoelectric effect in ZnO increase the charge-carrier separation, producing this reduction in recombination and associated efficiency increase.