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Updated: Jun 4, 2025
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Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
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Exciton spectra in disordered quantum wells.
V A Stephanovich1, W Olchawa1, A Bartecka1
1Institute of Physics, <a href="https://ror.org/04gbpnx96">University of Opole</a>, Oleska 48, 45-052 Opole, Poland.
Physical Review. E
|December 18, 2024
Summary
Disorder dramatically boosts exciton binding energy in semiconductor quantum wells (QWs), sometimes tenfold. This effect, influenced by disorder strength and angular momentum, has implications for optoelectronic and spintronic devices.
Area of Science:
- Condensed matter physics
- Quantum mechanics
- Semiconductor physics
Background:
- Exciton behavior in semiconductor quantum wells (QWs) is crucial for optoelectronic devices.
- Understanding the impact of structural disorder on exciton properties is essential for device performance.
Purpose of the Study:
- To investigate the influence of disorder on exciton spectra and binding energies in semiconductor quantum wells.
- To model disorder effects using the fractional Laplacian in Schrödinger equations for QW structures.
Main Methods:
- Introduced the fractional Laplacian to model disorder within the Schrödinger equation framework.
- Calculated exciton binding energies for ground and low-lying excited states.
- Analyzed the dependence of binding energy on QW size and disorder strength (Lévy index α).
Main Results:
- Disorder significantly increases exciton binding energy in QWs, up to a factor of 10.
- The interplay between disorder strength and exciton angular momentum effectively makes QW barriers appear infinite.
- This phenomenon impacts exciton binding energy calculations in disordered QWs.
Conclusions:
- Disorder is a critical factor enhancing exciton binding energies in quantum wells.
- The findings are applicable to various heterostructures (e.g., GaAs/AlGaAs, GaN/AlGaN) used in optoelectronics and spintronics.
- This research provides insights into designing advanced semiconductor devices with tailored exciton properties.
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