A Fused Ring Electron Acceptor with Decacyclic Core Enables over 13.5% Efficiency for Organic Solar Cells. Issue 30 (14th September 2018)

• Record Type: Journal Article
• Authors: He, Dan; Zhao, Fuwen; Xin, Jingming; Rech, Jeromy James; Wei, Zhixiang; Ma, Wei; You, Wei; Li, Bao; Jiang, Li; Li, Yongfang; Wang, Chunru
• Is Part Of: Advanced energy materials. Volume 8:Issue 30(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-09-14
• Subjects: additive optimization -- fused decacyclic unit -- fused ring electron acceptor -- organic solar cells -- power conversion efficiency; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201802050
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Extending π‐conjugation of donor units in fused ring electron acceptors (FREAs) promises to reinforce intramolecular charge transfer for smaller bandgaps, and enhances intermolecular interactions for higher charge mobility. Despite these advantages, power conversion efficiencies (PCEs) of FREAs with a large planar donor core are still below 12%. Herein, a fused decacyclic donor unit, IDC, is developed, and the FREA, IDCIC, whose optical bandgap is 1.45 eV, is synthesized. The FTAZ:IDCIC‐based organic solar cell (OSC) with a binary additive, chloronaphthalene and 1, 8‐diiodooctane (CN&DIO), affords a remarkable PCE of 13.58%, which is among the highest efficiencies of OSCs. The binary additive plays a crucial role in the morphology of FTAZ:IDCIC‐based OSCs. The addition of DIO promotes IDCIC to aggregate and enhances domain size and domain purity in FTAZ:IDCIC blend film for its poor solubility in DIO, while the addition of chloronaphthalene (CN) inhibits the aggregation, facilitates IDCIC to diffuse into the donor, and reduces domain size and domain purity for its excellent solubility in CN. The binary additive, CN&DIO, compromises the effect of the two; thus FTAZ:IDCIC‐based OSCs with 0.25% CN&DIO obtain moderate domain size and high domain purity simultaneously, achieving the least charge recombination for the highest J SC (21.98 mA cm −2 ) and fill factor (FF) (71.03%). Abstract : A new fused decacyclic unit is developed and used as the donor core to synthesize the fused ring electron acceptor, IDCIC. IDCIC exhibits a small optical bandgap of 1.45 eV with strong absorption in 600–830 nm. FTAZ:IDCIC‐based organic solar cells afford an impressive power conversion efficiency of 13.58% with high J SC (21.98 mA cm −2 ) and FF (71.03%) by using a binary additive of chloronaphthalene and 1, 8‐diiodooctane.