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Morphology Control for Fully Printable Organic–Inorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer
Published on: January 10, 2017
Solution-processable triindoles as hole selective materials in organic solar cells
Steve W Shelton1, Teresa L Chen, David E Barclay
1The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
ACS Applied Materials & Interfaces
|April 14, 2012
Summary
Two triindole derivatives, triazatruxene (TAT) and N-trimethyltriindole (TMTI), show promise as hole selective layers in organic solar cells. These materials enhance device efficiency by improving hole extraction and electron blocking, achieving up to a 26% increase in inverted devices.
Area of Science:
- Materials Science
- Organic Electronics
- Photovoltaics
Background:
- Organic solar cells (OSCs) require efficient charge transport layers.
- Hole selective layers (HSLs) are crucial for extracting holes and blocking electrons.
- Solution-processable organic molecules offer potential for low-cost OSC fabrication.
Purpose of the Study:
- To investigate the efficacy of triazatruxene (TAT) and N-trimethyltriindole (TMTI) as hole selective materials in OSCs.
- To evaluate their performance in both planar heterojunction and bulk heterojunction device architectures.
- To understand the role of their unique electronic and optical properties in device performance.
Main Methods:
- Synthesis and characterization of TAT and TMTI.
- Fabrication of planar heterojunction devices with TAT/TMTI and C60.
- Fabrication of inverted bulk heterojunction devices with a TAT interfacial layer.
- Device performance evaluation using photovoltaic measurements and cyclic voltammetry.
Main Results:
- TAT and TMTI exhibit wide bandgaps and suitable energy levels (LUMO: -1.68 eV/-2.05 eV, HOMO: -5.03 eV/-5.1 eV) for hole extraction.
- Planar devices achieved efficiencies up to 0.71% (TAT) and 0.87% (TMTI).
- Incorporating a TAT layer in inverted P3HT:PCBM devices boosted efficiency by 26%.
Conclusions:
- TAT and TMTI are effective solution-processable hole selective materials for organic solar cells.
- Their properties enable efficient hole extraction and electron blocking, enhancing device performance.
- These triindoles represent promising candidates for improving OSC efficiency and processability.
