Related Experiment Video
Updated: Jul 8, 2025
06:16
Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
Published on: December 21, 2017
5.7K
Spontaneous Modulation Doping in Semi-Crystalline Conjugated Polymers Leads to High Conductivity at Low Doping
Aditya Dash1, Shubhradip Guchait2, Dorothea Scheunemann1
1Institute for Molecular Systems Engineering and Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany.
Advanced Materials (Deerfield Beach, Fla.)
|December 20, 2023
Summary
Researchers achieved high conductivity in organic semiconductors by enabling spontaneous "bottom-up" modulation doping. This method spatially separates dopants from charge carriers, preserving mobility and enhancing performance.
Area of Science:
- Materials Science
- Organic Electronics
- Semiconductor Physics
Background:
- Controlling charge carrier density via doping is crucial for semiconductors.
- Organic semiconductors face challenges with doping, including reduced mobility and introduced traps.
- Modulation doping, successful in inorganic semiconductors, has not been applied to organic systems.
Purpose of the Study:
- To investigate spontaneous, bottom-up modulation doping in organic semiconductors.
- To overcome the limitations of traditional doping methods in organic materials.
- To achieve high charge carrier mobility and conductivity in organic semiconductors.
Main Methods:
- Experimental investigation of carefully selected host/dopant combinations.
- Numerical simulations to understand dopant behavior and charge transport.
- Analysis of material morphology and microstructure.
Main Results:
- Demonstrated spontaneous, bottom-up modulation doping in organic semiconductors.
- Achieved spatial separation of dopants in amorphous phases and charge transport in crystalline phases.
- Observed exceptionally high conductivities at low dopant concentrations.
Conclusions:
- Spatially separating dopants from charge transport pathways preserves microstructure and enhances mobility.
- Spontaneous modulation doping offers a promising strategy for high-performance organic electronics.
- This approach overcomes key limitations of conventional doping in organic semiconductors.
Related Concept Videos
01:20Types of Semiconductors
611
Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
611
01:18Fermi Level
609
The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
609
01:21Polymer Classification: Crystallinity
2.9K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.9K
02:35Band Theory
15.2K
When two or more atoms come together to form a molecule, their atomic orbitals combine and molecular orbitals of distinct energies result. In a solid, there are a large number of atoms, and therefore a large number of atomic orbitals that may be combined into molecular orbitals. These groups of molecular orbitals are so closely placed together to form continuous regions of energies, known as the bands.
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
15.2K
01:26Polymer Classification: Stereospecificity
2.4K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
2.4K
01:24Metal-Semiconductor Junctions
352
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
352