Charge transport in disordered materials with exponentially distributed density of states

• Published in: Journal of non-crystalline solids 2024-09, Vol.640, p.123115, Article 123115
• Main Authors: Li, Siyan, Yu, Jiayang, Zhu, Ye, Zhang, Tianyou
• Format: Article
• Language: English
• Subjects: Carrier mobility; Exponential; Percolation model; Transport energy; Trap filling effect
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2024.123115

•Transport energy of disordered semiconductors with exponential density of states is systematically analyzed.•To get a reasonable value of transport energy, a symmetric exponential density of states is introduced.•Dependences of transport energy on parameters like tailing factor, carrier concentration and initial energy of a hop are investigated with a consideration of trap filling effect.•The calculated results are confirmed using the famous percolation model and typical experimental data from both small molecular and polymeric materials. Transport energy of disordered semiconductors with exponential density of states is systematically analyzed. To avoid getting an invalid value of transport energy, a symmetric exponential density of states is introduced. Dependences of transport energy on parameters like tailing factor, carrier concentration and initial energy of a hop are investigated with a consideration of trap filling effect. The obtained transport energy is used to calculate the carrier mobility of disordered semiconductors with both narrow and broad states distributions. The calculated results are confirmed using the famous percolation model and typical experimental data. The effects of electric field and polaron effect on the distribution of the transport energy are also discussed. These findings are of great importance to understand the carrier transport mechanism in disordered materials.