High efficiency non-fullerene organic tandem photovoltaics based on ternary blend subcells

Wenchao Huang, Sheng-Yung Chang, Pei Cheng, Dong Meng, Bowen Zhu, Selbi Nuryyeva, Chenhui Zhu, Lijun Huo, Zhaohui Wang, Mingkui Wang, Yang Yang

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14 Citations (Scopus)

Abstract

The application of tandem structure that integrates multiple subcells into one device is a promising way to realize high efficiency organic solar cells. However, current-matching among different subcells remains as the main challenge for organic tandem photovoltaics. Here, we provide a facile approach to achieve a good current matching via engineering the chemical composition of non-fullerene ternary blend subcells. For the front subcell, a ternary blend of PDBT-T1:TPH-Se:ITIC is selected due to its good thermal stability. The amorphous nature of TPH-Se can sufficiently suppress the unfavorable phase separation of blends during the heat treatment, enabling a sintering in the fabrication of high quality interconnecting layer. A double-junction tandem device is fabricated with a rear subcell consisting of PBDB-T:ITIC. After the optimization of the chemical composition of the front subcell, the power conversion efficiency (PCE) of double-junction tandem device increased from 10.6% using PDBT-T1:TPH-Se binary front subcell to 11.5% using PDBT-T1:TPH-Se:ITIC (1:0.9:0.1) ternary front subcell due to better current matching. In order to further enhance the light absorption in the near-infrared region, a third junction PBDTTT-EFT:IEICO-4F is introduced. The champion cell of triple-junction non-fullerene tandem solar cell achieves a PCE of 13.0% with a high open circuit voltage of 2.52 V.

Original languageEnglish
Pages (from-to)7977-7984
Number of pages8
JournalNano Letters
Volume18
Issue number12
DOIs
Publication statusPublished - 12 Dec 2018
Externally publishedYes

Keywords

  • current matching
  • morphology
  • non-fullerene
  • Organic tandem photovoltaics
  • ternary subcell

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