Exploration of efficient electron acceptors for organic solar cells: rational design of indacenodithiophene based non-fullerene compounds

AbstractThe global need for renewable sources of energy has compelled researchers to explore new sources and improve the efficiency of the existing technologies. Solar energy is considered to be one of the best options to resolve climate and energy crises because of its long-term stability and pollution free energy production. Herein, we have synthesized a small acceptor compound (TPDR) and have utilized for rational designing of non-fullerene chromophores (TPD1–TPD6) using end-capped manipulation in A2–A1–D–A1–A2 configuration. The quantum chemical study (DFT/TD-DFT) was used to characterize the effect of end group redistribution through frontier molecular orbital (FMO), optical absorption, reorganization energy, open circuit voltage (Voc), photovoltaic properties and intermolecular charge transfer for the designed compounds. FMO data exhibited that TPD5 had the least ΔE (1.71 eV) with highest maximum absorption (λmax) among all compounds due to the four cyano groups as the end-capped acceptor moieties. The reorganization energies of TPD1–TPD6 hinted at credible electron transportation due to the lower values of λe than λh. Furthermore, open circuit voltage (Voc) values showed similar amplitude for all compounds including parent chromophore, except TPD4 and TPD5 compounds. These designed compounds with unique end group acceptors have the potential to be used as novel fabrication materials for energy devices.

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Exploration of promising optical and electronic properties of (non-polymer) small donor molecules for organic solar cells

Scientific Reports ◽

10.1038/s41598-021-01070-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Muhammad Khalid ◽

Muhammad Usman Khan ◽

Saeed Ahmed ◽

Zahid Shafiq ◽

Mohammed Mujahid Alam ◽

...

Keyword(s):

Density Functional Theory ◽

Solar Cells ◽

Organic Solar Cells ◽

Density Functional ◽

Reorganization Energy ◽

Energy Difference ◽

Open Circuit ◽

Frontier Molecular Orbital ◽

Functional Theory ◽

Td Dft

AbstractNon-fullerene based organic compounds are considered promising materials for the fabrication of modern photovoltaic materials. Non-fullerene-based organic solar cells comprise of good photochemical and thermal stability along with longer device lifetimes as compared to fullerene-based compounds. Five new non-fullerene donor molecules were designed keeping in view the excellent donor properties of 3-bis(4-(2-ethylhexyl)-thiophen-2-yl)-5,7-bis(2ethylhexyl) benzo[1,2-:4,5-c′]-dithiophene-4,8-dione thiophene-alkoxy benzene-thiophene indenedione (BDD-IN) by end-capped modifications. Photovoltaic and electronic characteristics of studied molecules were determined by employing density functional theory (DFT) and time dependent density functional theory (TD-DFT). Subsequently, obtained results were compared with the reference molecule BDD-IN. The designed molecules presented lower energy difference (ΔΕ) in the range of 2.17–2.39 eV in comparison to BDD-IN (= 2.72 eV). Moreover, insight from the frontier molecular orbital (FMO) analysis disclosed that central acceptors are responsible for the charge transformation. The designed molecules were found with higher λmax values and lower transition energies than BDD-IN molecule due to stronger end-capped acceptors. Open circuit voltage (Voc) was observed in the higher range (1.54–1.78 V) in accordance with HOMOdonor–LUMOPC61BM by designed compounds when compared with BDD-IN (1.28 V). Similarly, lower reorganization energy values were exhibited by the designed compounds in the range of λe(0.00285–0.00370 Eh) and λh(0.00847–0.00802 Eh) than BDD-IN [λe(0.00700 Eh) and λh(0.00889 Eh)]. These measurements show that the designed compounds are promising candidates for incorporation into solar cell devices, which would benefit from better hole and electron mobility.

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High open circuit voltage organic solar cells based upon fullerene free bulk heterojunction active layers

Canadian Journal of Chemistry ◽

10.1139/cjc-2014-0099 ◽

2014 ◽

Vol 92 (10) ◽

pp. 932-939 ◽

Cited By ~ 4

Author(s):

Ala’a F. Eftaiha ◽

Jon-Paul Sun ◽

Arthur D. Hendsbee ◽

Casper Macaulay ◽

Ian G. Hill ◽

...

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Open Circuit Voltage ◽

Field Effect Transistors ◽

Bulk Heterojunction ◽

Energy Levels ◽

Open Circuit ◽

Frontier Molecular Orbital ◽

Orbital Energy ◽

High Electron

We have recently reported on a small organic molecule containing a bithiophene core with end-capping phthalimide units (PthTh2Pth) that exhibited a H-aggregation tendency in the solid state and high electron mobility in organic field effect transistors. In this contribution, we have studied both the physical and electrical properties of poly(3-hexylthiophene) (P3HT) and PthTh2Pth thin films by measuring the optical absorption, Frontier molecular orbital energy levels, photoluminescence quenching, thermal properties, and photovoltaic response. Our results have provided a useful insight into the use of PthTh2Pth as an electron acceptor material for organic photovoltaic applications. In comparison with high-performance, fullerene-based, solution-processed bulk heterojunction solar cells reported in the literature, a relatively high open circuit voltage (∼0.94 V) was obtained for various donor–acceptor blend ratios. These results highlight the potential for PthTh2Pth to act as an alternative to fullerenes as acceptors in organic solar cell devices.

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Importance of interfacial crystallinity to reduce open-circuit voltage loss in organic solar cells

Applied Physics Letters ◽

10.1063/1.5114670 ◽

2019 ◽

Vol 115 (15) ◽

pp. 153301 ◽

Cited By ~ 5

Author(s):

Seiichiro Izawa ◽

Naoto Shintaku ◽

Mitsuru Kikuchi ◽

Masahiro Hiramoto

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Open Circuit Voltage ◽

Open Circuit ◽

Voltage Loss

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Facile synthesis and photovoltaic applications of a new alkylated bismethano fullerene as electron acceptor for high open circuit voltage solar cells

RSC Advances ◽

10.1039/c5ra10089e ◽

2015 ◽

Vol 5 (79) ◽

pp. 64724-64730 ◽

Cited By ~ 15

Author(s):

Derya Baran ◽

Sule Erten-Ela ◽

Andreas Kratzer ◽

Tayebeh Ameri ◽

Christoph J. Brabec ◽

...

Keyword(s):

Solar Cells ◽

Electron Acceptor ◽

Organic Solar Cells ◽

Open Circuit Voltage ◽

Open Circuit ◽

Facile Synthesis ◽

Photovoltaic Applications ◽

Lumo Level

In this work, a bis-adduct C60 derivative was facilely synthesized using an alkyl solubilizing group. This semiconductor offers a higher LUMO level compared to PCBM, which resulted in a significantly enhanced Voc of 0.73 V in organic solar cells.

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Corrigendum to “Electronic properties of small molecule-diketopyrrolopyrrole derivatives and a correlation with the open circuit voltage in organic solar cells” [Synth. Met. 162 (9–10) (2012) 748–752]

Synthetic Metals ◽

10.1016/j.synthmet.2012.06.002 ◽

2012 ◽

Vol 162 (15-16) ◽

pp. 1483

Author(s):

Jung Hwa Seo

Keyword(s):

Solar Cells ◽

Electronic Properties ◽

Small Molecule ◽

Organic Solar Cells ◽

Open Circuit Voltage ◽

Open Circuit

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Independent control of open-circuit voltage of organic solar cells by changing film thickness of MoO3 buffer layer

Applied Physics Letters ◽

10.1063/1.2949321 ◽

2008 ◽

Vol 92 (24) ◽

pp. 243309 ◽

Cited By ~ 75

Author(s):

Yoshiki Kinoshita ◽

Rie Takenaka ◽

Hideyuki Murata

Keyword(s):

Solar Cells ◽

Film Thickness ◽

Buffer Layer ◽

Organic Solar Cells ◽

Open Circuit Voltage ◽

Open Circuit ◽

Independent Control

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Impact of mesoscale order on open-circuit voltage in organic solar cells

Nature Materials ◽

10.1038/nmat4167 ◽

2014 ◽

Vol 14 (4) ◽

pp. 434-439 ◽

Cited By ~ 131

Author(s):

Carl Poelking ◽

Max Tietze ◽

Chris Elschner ◽

Selina Olthof ◽

Dirk Hertel ◽

...

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Open Circuit Voltage ◽

Open Circuit

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Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.171 ◽

2018 ◽

Vol 9 ◽

pp. 1802-1808 ◽

Cited By ~ 6

Author(s):

Katherine Atamanuk ◽

Justin Luria ◽

Bryan D Huey

Keyword(s):

Solar Cells ◽

Open Circuit Voltage ◽

Short Circuit ◽

Photovoltaic Performance ◽

Three Dimensional ◽

Short Circuit Current ◽

Open Circuit ◽

Photovoltaic Properties ◽

Order Of Magnitude ◽

Individual Grains

The nanoscale optoelectronic properties of materials can be especially important for polycrystalline photovoltaics including many sensor and solar cell designs. For thin film solar cells such as CdTe, the open-circuit voltage and short-circuit current are especially critical performance indicators, often varying between and even within individual grains. A new method for directly mapping the open-circuit voltage leverages photo-conducting AFM, along with an additional proportional-integral-derivative feedback loop configured to maintain open-circuit conditions while scanning. Alternating with short-circuit current mapping efficiently provides complementary insight into the highly microstructurally sensitive local and ensemble photovoltaic performance. Furthermore, direct open-circuit voltage mapping is compatible with tomographic AFM, which additionally leverages gradual nanoscale milling by the AFM probe essentially for serial sectioning. The two-dimensional and three-dimensional results for CdTe solar cells during in situ illumination reveal local to mesoscale contributions to PV performance based on the order of magnitude variations in photovoltaic properties with distinct grains, at grain boundaries, and for sub-granular planar defects.

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