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Tuning charge transport in solution-sheared organic semiconductors using lattice strain
Gaurav Giri1, Eric Verploegen, Stefan C B Mannsfeld
1Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA.
Nature
|December 24, 2011
Summary
Researchers developed a solution-processing technique to improve organic semiconductor performance by introducing lattice strain. This method enhances charge carrier mobility, crucial for flexible and low-cost electronics.
Area of Science:
- Materials Science
- Organic Electronics
- Solid State Physics
Background:
- Organic semiconductors are key for flexible, transparent, and low-cost electronics.
- Improving charge carrier mobility in solution-processed organic semiconductors is essential for device performance.
- Lattice strain in inorganic semiconductors enhances charge carrier mobility.
Purpose of the Study:
- To develop a solution-processing technique for organic semiconductors that utilizes lattice strain to increase charge carrier mobility.
- To investigate the effect of lattice strain on molecular packing and electron orbital overlap in organic semiconductors.
- To achieve higher charge carrier mobilities in organic semiconductor devices.
Main Methods:
- A novel solution-processing technique was employed to introduce controlled lattice strain in organic semiconductors.
- The π-π stacking distance of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) was systematically reduced through applied strain.
- Organic field-effect transistors (OFETs) were fabricated using strained and unstrained TIPS-pentacene films to measure charge carrier mobility.
Main Results:
- The π-π stacking distance in TIPS-pentacene was reduced from 3.33 Å to 3.08 Å, the shortest reported for organic semiconductor crystal lattices.
- Electron orbital overlap between conjugated backbones was significantly increased due to the reduced π-π stacking distance.
- Positive charge carrier (hole) mobility in TIPS-pentacene transistors increased from 0.8 cm²V⁻¹s⁻¹ (unstrained) to 4.6 cm²V⁻¹s⁻¹ (strained).
Conclusions:
- Solution processing combined with lattice strain is an effective strategy to enhance charge carrier mobility in organic semiconductors.
- This technique offers a pathway to developing high-performance, low-cost organic electronic devices.
- Controlling molecular packing via lattice strain is crucial for optimizing organic semiconductor performance.
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