Cyanine Dye as Dopant Free Hole Transport Material in Perovskite Solar Cells

摘要

Molecularly engineered, low cost cyanine dye was synthesized and used as hole transport layer (HTL) for Perovskite solar cells. The photo-physical properties were studied using solutions and films of pristine as well as hybrid/film structure of cyanine with PbI2. UV-Vis spectroscopy of the cyanine-PbI2 hybrid material reveals a strong coupling between the chromophores in the solid state. Perovskite solar cells were fabricated using either spiro-OMeTAD or cyanine as dopant free HTL. In case of Spiro-OMeTAD as dopant free HTL, PCE of 9.91% was achieved with V_oc of 1.02 V, J_sc of 22.3 mA/cm², and FF of 0.43. On the other hand using cyanine as HTL affords a large enhancement of PCE (15.4 %) as well as other cell parameters including V_oc (1.12 V), J_sc (21.2 mA/cm²), and in particular FF (0.65), due to reduction of charge recombination in addition to the improved charge collection and transporting using Cyanine HTL.