Vacuum-Deposited Biternary Organic Photovoltaics

Journal Article · Thu Oct 17 00:00:00 EDT 2019 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/jacs.9b09012· OSTI ID:1573354

Li, Yongxi  ^[1]; Sheriff, Hafiz K. M. ^[2]; Liu, Xiao  ^[1]; Wang, Chun-Kai ^[3]; Ding, Kan ^[1]; Han, Han ^[3]; Wong, Ken-Tsung  ^[4]; Forrest, Stephen R.  ^[5]

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1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Electrical Engineering, Dept. of Material Science and Engineering, and Dept. of Physics
2. Univ. of Michigan, Ann Arbor, MI (United States). Applied Physics Program
3. National Taiwan Univ., Taipei (Taiwan). Dept. of Chemistry
4. National Taiwan Univ., Taipei (Taiwan). Dept. of Chemistry; Academia Sinica, Taipei (Taiwan). Inst. of Atomic and Molecular Science
5. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Electrical Engineering, Dept. of Material Science and Engineering, Dept. of Physics, and Applied Physics Program

Ternary blend organic photovoltaics (OPVs) have been introduced to improve solar spectral absorption and reduce energy losses beyond that of binary blend OPVs, but the difficulties in simultaneously optimizing the morphology of three molecular components results in devices that have generally exhibited performance inferior to analogous binary OPVs. In this paper, we introduce a small molecule-based bi-ternary OPV comprising two individual, vacuum deposited binary bulk heterojunctions fused at a planar junction without component intermixing. In contrast to previous reports where the open circuit voltage (V_OC) of a conventional, blended ternary cell lies between that of the individual binaries, the V_OC of the bi-ternary OPV corresponds to one of the constituent binaries, depending on the order in which they are stacked relative to the anode. Additionally, dipole-induced energy-level realignment between the two binary segments necessary to achieve maximum efficiency is observed only when using donor-acceptor-acceptor’ dipolar donors in the photoactive heterojunctions. The optimized bi-ternary OPV shows improved performance compared to its two constituent binary OPVs, achieving a power conversion efficiency of 10.6 ± 0.3% under AM 1.5G 1 sun (100 mW/cm²) simulated illumination with V_OC = 0.94 ± 0.01 V, a short circuit current density of 16.0 ± 0.5 mA cm^-2 and a fill factor of 0.70 ± 0.01.

• Research Organization: Univ. of Michigan, Ann Arbor, MI (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: EE0008561
• OSTI ID: 1573354
• Journal Information: Journal of the American Chemical Society, Vol. 141, Issue 45; ISSN 0002-7863
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY