Abstract
Ga-rich CuIn(1-x)GaxSe2 (CIGS) quantum dots (QDs) with a wide bandgap of 1.58 eV were utilized in dye-sensitized solar cells for energy harvesting. Ga-rich CIGS QDs at TiO2 photoanodes afford the recombination reduction and thus suppress the dark current, leading to the increase of short-circuit current from 14.47 to 15.27 mA.cm(-2) and open-circuit voltage from 751 to 762 mV. This is due to well-adjusted conduction band minimum of Ga-rich CIGS QDs between that of TiO2 and excited state oxidation potential of N719, enhancing the photoelectron collection and suppressing electron back-transfer from TiO2 to oxidized redox species in the electrolyte. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4751469]