Abstract
While the outstanding charge transport and sunlight-harvesting properties of porphyrin molecules are highly attractive as active materials for organic photovoltaic (OPV) devices, the development of n-type porphyrin-based electron acceptors has been challenging. In this work, we developed a high-performance porphyrin-based electron acceptor for OPVs by substitution of four naphthalene diimide (NDI) units at the perimeter of a Zn-porphyrin (P Zn ) core using ethyne linkage. Effective π-conjugation between four NDI wings and the P Zn core significantly broadened Q-band absorption to the near infrared region, thereby achieving the narrow band gap of 1.33 eV. Employing a windmill-structured tetra-NDI substituted P Zn -based acceptor (P Zn -TNDI) and mid-band gap polymer donor (PTB7-Th), the bulk heterojunction OPV devices achieved a power conversion efficiency (PCE) of 8.15% with an energy loss of 0.61 eV. The PCE of our P Zn -TNDI-based device was the highest among the reported OPVs using porphyrin-based acceptors. Notably, the amorphous characteristic of P Zn -TNDI enabled optimization of the device performance without using any additive, which should make industrial fabrication simpler and cheaper.
Original language | English (US) |
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Pages (from-to) | 41344-41349 |
Number of pages | 6 |
Journal | ACS Applied Materials and Interfaces |
Volume | 10 |
Issue number | 48 |
DOIs | |
State | Published - Dec 5 2018 |
Keywords
- n-type porphyrins
- near-infrared absorption
- nonfullerene acceptors
- organic photovoltaics
- porphyrins
ASJC Scopus subject areas
- General Materials Science