Related Experiment Video
Updated: May 18, 2026

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
How to find out the density of states in disordered organic semiconductors
J O Oelerich1, D Huemmer, S D Baranovskii
1Department of Physics and Material Sciences Center, Philipps-University, D-35032 Marburg, Germany.
Abstract:
We suggest a recipe on how to determine the density of states (DOS) in disordered organic semiconductors from the measured dependence of the charge carrier mobility on the concentration of carriers n. The recipe is based on a theory for the concentration-dependent mobility. As an example, we apply our theoretical results to experimental data obtained on two polymers and show that from the class of trial DOS functions g(ε)∝exp{-(ε/σ)(p)}, only those with p>1.8 can explain the experimental results. In particular, we claim that the concentration-independent mobility at low n evidences that the DOS cannot be purely exponential, which is in contrast to numerous recent assumptions in the literature.
Related Concept Videos
Semiconductors
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Energy Bands in Solids
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states that no two...
Band Theory
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
Polymers: Molecular Weight Distribution
Types of Semiconductors
Fermi Level Dynamics
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...

