Details

Autor(en) / Beteiligte

• Lee, Jinho
• Lee, Jong-Hoon
• Yao, Huifeng
• Cha, Hyojung
• Hong, Soonil
• Lee, Seongyu
• Kim, Jehan
• Durrant, James R
• Hou, Jianhui
• Lee, Kwanghee

Titel

Efficient and photostable ternary organic solar cells with a narrow band gap non-fullerene acceptor and fullerene additive

Ist Teil von

• Journal of materials chemistry. A, Materials for energy and sustainability, 2020-04, Vol.8 (14), p.6682-6691

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Recent breakthroughs in molecular design have allowed for remarkable achievement in the field of non-fullerene acceptor (NFA)-based organic solar cells (OSCs) with high power conversion efficiencies (PCEs) of over 15%. However, despite such promising advances, the inferior stability of OSCs under operating conditions remains a prominent challenge that must be overcome for their practical realization. Here, versatile ternary photoactive systems with simultaneously enhanced efficiency and photostability are developed by introducing a small amount of fullerene (PC 71 BM) into a narrow band gap NFA-based bulk heterojunction nanocomposite (PTB7-Th:IEICO-4F); this approach leads to an enhanced PCE of 10.55% and a prolonged lifetime, retaining approximately 80% of the initial PCE after 500 h of operation under continuous illumination. Based on the energy levels and surface energies of the component materials, cascade energetic alignment facilitates electron transfer without trapping. The PTB7-Th/PC 71 BM interface provides an energy barrier to suppress recombination between holes in PTB7-Th and electrons in IEICO-4F. Moreover, a small amount of PC 71 BM promotes favorable molecular packing and orientation of IEICO-4F, leading to enhanced electron mobility and balanced charge transport. A study using transient absorption spectroscopy reveals that the ternary blend effectively suppresses the evolution of charge recombination. The simultaneous enhancement of efficiency and photostability in organic solar cells is successfully achieved by introducing a fullerene acceptor as a solid additive into anon-fullerene bulk heterojunction system.