Photovoltaic performance of solid-state DSSCs sensitized with organic isophorone dyes: Effect of dye-loaded amount and dipole moment

Two isophorone sensitizers (S4 and D-3) were utilized in solid-state dye-sensitized solar cells (DSSCs) using spiro-OMeTAD as hole-transporting material. The dye-loaded amount of D-3 was almost 1.5 times as that of 54 which lead to higher light harvesting efficiency than S4. Moreover, the larger dipole moment along the direction for D-3 could cause more negative charges located close to the TiO2 surface than that of S4, resulting in a larger conduction band (CB) upshift of TiO2 for D-3 which was beneficial to an increase of V-oc. Promising results sensitized by D-3 in solid-state DSSCs were achieved with a short-circuit photocurrent density (J(sc)) of 3.4 mA cm(-2), an open-circuit photovoltage (V-oc) of 760 mV, a fill factor (FF) of 0.71, and an overall efficiency (eta) of 1.92% while ruthenium dye N3 produced a eta of 2.55% under the same conditions (AM 1.5, 100 mW cm(-2)). (C) 2011 Elsevier Ltd. All rights reserved.