Screened Coulomb interaction in insulators with strong disorder.

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Excitons in semiconductors are crucial for optical and electronic properties.
• Screened Coulomb interaction and disorder are key factors influencing exciton behavior.
• Polymeric semiconductors and van der Waals structures exhibit complex excitonic phenomena.

Purpose of the Study:

• To investigate the combined effects of dielectric screening and disorder on excitons.
• To analyze exciton behavior in systems like polymeric semiconductors and van der Waals structures.
• To understand the implications of these effects on semiconductor device performance.

Main Methods:

• Phenomenological modeling of disorder using the fractional Schrödinger equation.
• Analysis of the screened hydrogenic problem.
• Theoretical investigation of exciton properties under varying screening and disorder levels.

Main Results:

• Joint action of screening and disorder can destroy excitons under strong screening.
• Moderate screening and disorder can enhance electron-hole binding, leading to exciton collapse.
• Observed effects may relate to quantum manifestations of chaotic exciton behavior.

Conclusions:

• The interplay between dielectric screening and disorder significantly impacts exciton stability and properties.
• Exciton collapse due to screening and disorder has implications for semiconductor device applications.
• Theoretical framework allows prediction of excitonic properties in disordered and screened semiconductor systems.