I have tried solving for the exciton energy in GaAs/AlAs QWs but my calculated results do not agree with published experimental results.(adsbygoogle = window.adsbygoogle || []).push({});

My model in the calculation is just a single GaAs well with AlAs barriers. Using the material parameters of both materials, and the well width, I calculated the heavy-hole exciton energy as

Ehh = E_gap_GaAs + EcQw + EhhQw - Ryd*4

where E_gap_GaAs is the GaAs band gap energy

EcQw and EhhQw are the first energy levels of the QW

Ryd is the 3D Rydberg energy accounting for the binding energy part

However, all my calculations are always smaller than the experimental results even if I remove the binding energy. Now, I'm beginning to wonder what is the effect of multiple QWs or embedding a single QW on a superlatice on the exciton energy.

By the way, I used the finite well model to calculate the quantized energy levels---those that involve the tangent something found in undergrad quantum physics.

QUESTIONS:

1. What is the effect of multiple quantum wells or embedding a single QW in a superlattice on the exciton energy? On the effective band gap (i mean without excitonic effects)?

2. Are there simple models (for multiple QWs) to calculate those energies?

Thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Excitons in Multiple QWs

**Physics Forums | Science Articles, Homework Help, Discussion**