Dye Sensitization of ZnO by Unsymmetrical Squaraine Dyes Suppressing Aggregation

Abstract We have developed an efficient, cyan-colored, and novel squaraine-dye-sensitized ZnO solar cell, producing a maximum incident photon-to-electron conversion efficiency (IPCE) of 59% at 630 nm. The solar cell sensitized by Sq 3 having bulky groups to prevent aggregation of dyes has achieved a 1.5% solar-to-electricity conversion efficiency (η) with a short-circuit current density of 4.04 mA cm−2, an open-circuit photovoltage of 0.61 V, and a fill factor of 0.61 under standard AM 1.5 irradiation (100 mW cm−2).