Metal‐Free Organic Dyes with Double Auxiliary Acceptors for High‐Performance Dye‐Sensitized Solar Cells

Abstract

Dye‐sensitized solar cells (DSSCs) have continuously received attentions in the field of photovoltaics due to their charming properties and promising performance under the indoor dim‐light environment. Herein, two organic photosensitizers ( GZ121 and GZ124) are designed with the insertion of double auxiliary acceptors in a donor‐acceptor‐π‐acceptor‐π‐acceptor (D‐A‐π‐A‐π‐A) design. The devices fabricated from these photosensitizers are investigated under one sun and dim‐light (300–6000 lux) conditions with N719 dye for comparison. The GZ124 dye achieves power conversion efficiencies (PCEs) of 9.43% (photocurrent density ( J sc ) = 14.79 mA cm −2 , photovoltage ( V oc ) = 0.85 V, and fill factor (FF) = 0.75) under one sun irradiation and 28.62% ( J sc = 0.99 mA cm −2 , V oc = 0.68 V, and FF = 0.77) under dim‐light illumination at 6000 lux, which is far better than the reference N719 dye. Moreover, the PCE under dim light is ranked among the top as compared to DSSCs devices sensitized by a single dye. The GZ124 dye also demonstrates outstanding stability for more than 1000 h under prolonged one sun sensitization. The current studies affirm that the design of a D‐A‐π‐A‐π‐A structural framework by introducing double auxiliary acceptors in a single sensitizer is a promising approach to boost the performance of DSSCs.