Prolonging charge separation in P3HT-SWNT composites using highly enriched semiconducting nanotubes
Josh M Holt1, Andrew J Ferguson, Nikos Kopidakis
1Chemical and Materials Science Center, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, United States.
Nano Letters
|October 14, 2010
Summary
Metallic nanotubes hinder organic photovoltaics (OPVs) performance. Enriching blends with semiconducting single-walled carbon nanotubes (SWNTs) improves power conversion efficiency by increasing long-lived charge carriers.
Area of Science:
- Materials Science
- Nanotechnology
- Renewable Energy
Background:
- Single-walled carbon nanotubes (SWNTs) show promise for organic photovoltaics (OPVs).
- Current OPV power conversion efficiencies are limited, with underlying reasons not fully understood.
- Effective dispersion of SWNTs within polymer matrices is crucial for device performance.
Purpose of the Study:
- To investigate the impact of metallic and semiconducting SWNTs on OPV performance.
- To demonstrate effective redispersion of isolated SWNTs into poly(3-hexylthiophene) (P3HT).
- To provide experimental evidence for the detrimental effects of metallic SWNTs.
Main Methods:
- Preparation of highly enriched semiconducting and metallic SWNT blends.
- Incorporation of enriched SWNTs into poly(3-hexylthiophene) (P3HT) matrix.
- Time-resolved microwave conductivity measurements to assess carrier dynamics.
Main Results:
- Effective redispersion of isolated, enriched SWNTs into P3HT was achieved.
- The first experimental evidence showing the negative impact of metallic nanotubes on device performance was obtained.
- Incorporating highly enriched semiconducting SWNTs significantly increased the long-lived carrier population.
Conclusions:
- Metallic SWNTs negatively affect OPV performance.
- Highly enriched semiconducting SWNTs can enhance charge carrier populations in polymer composites.
- Optimizing SWNT purity is critical for advancing OPV technology.
