Higher Mobility and Carrier Lifetimes in Solution‐Processable Small‐Molecule Ternary Solar Cells with 11% Efficiency
Abstract
Solution‐processed small molecule (SM) solar cells have the prospect to outperform their polymer‐fullerene counterparts. Considering that both SM donors/acceptors absorb in visible spectral range, higher expected photocurrents should in principle translate into higher power conversion efficiencies (PCEs). However, limited bulk‐heterojunction (BHJ) charge carrier mobility (‐4 cm2 V‐1 s‐1) and carrier lifetimes (71BM can be used to achieve SM‐based ternary BHJ solar cells with active layer thicknesses >200 nm and PCEs nearing 11%. The examinations show that these remarkable figures are the result of i) significantly improved electron mobility (8.2 × 10‐4 cm2 V‐1 s‐1), ii) longer carrier lifetimes (2.4 µs), and iii) reduced geminate recombination within BHJ active layers to which PC71BM has been added as ternary component. Optically thick (up to ≈500 nm) devices are shown to maintain PCEs >8%, and optimized DR3:ICC6:PC71BM solar cells demonstrate long‐term shelf stability (dark) for >1000 h, in 55% humidity air environment.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 20, 2018
- Source ID
- 10.1002/aenm.201802836
Entities
People
- Frédéric Laquai
- Markus Wohlfahrt
- Maxime Babics
- Michael F. Toney
- Nimer Wehbe
- Pierre M. Beaujuge
- Ru-Ze Liang
- Shengjian Liu
- Tainan Duan
- Victoria Savikhin
- Yiming Zhang
- Zhipeng Kan
Organizations
- King Abdullah University of Science and Technology
- SLAC National Accelerator Laboratory
- Stanford University
- United States Department of Defense
- United States Department of Energy