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Ground-state electron transfer in all-polymer donor-acceptor heterojunctions
Kai Xu1, Hengda Sun2, Tero-Petri Ruoko1
1Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden.
Nature Materials
|March 11, 2020
Summary
Researchers achieved stable electrical conductivity in all-polymer systems by creating donor-acceptor interfaces. This novel doping method avoids molecular dopants, enhancing stability for organic electronic devices.
Area of Science:
- Materials Science
- Organic Electronics
- Polymer Chemistry
Background:
- Doping is essential for organic (opto)electronic devices.
- Traditional doping methods using heterogeneous molecules lead to poor stability and performance.
- Charge transfer in small-molecule systems offers stable conductivity, but this approach is unexplored in all-conjugated polymers.
Purpose of the Study:
- To report ground-state electron transfer in all-polymer donor-acceptor heterojunctions.
- To explore a new doping strategy for all-conjugated polymer systems.
- To investigate the potential for high and stable electrical conductivities without molecular dopants.
Main Methods:
- Fabrication of all-polymer donor-acceptor heterojunctions.
- Combining polymers with low-ionization energy and high-electron affinity.
- Characterization of electrical resistivity and charge carrier concentrations.
Main Results:
- Achieved resistivity values five to six orders of magnitude lower than single-layer polymers.
- Observed quasi-two-dimensional electron and hole distributions with concentrations of ~10^13 cm^-2.
- Demonstrated exceptional thermal stability in 3D bulk heterojunctions due to the absence of molecular dopants.
Conclusions:
- Ground-state electron transfer in all-polymer heterojunctions provides a stable and high-conductivity doping alternative.
- This approach eliminates issues associated with molecular dopant sublimation and aggregation.
- The findings are promising for developing electro-active composites for applications like thermoelectrics and wearable electronics.
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