Help: What is Band-Edge and Near-Band-Edge Emission?

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SUMMARY

Band-edge emission in direct band gap semiconductors is defined by the recombination of electrons and holes at the edges of the conduction and valence bands. Near-band-edge emission, however, indicates the presence of additional energy levels within the forbidden band, often attributed to excitonic states or shallow trap states. Understanding these emissions is crucial for applications in optoelectronics and semiconductor physics.

PREREQUISITES
  • Knowledge of direct band gap semiconductors
  • Understanding of photoluminescence principles
  • Familiarity with excitonic states
  • Basic concepts of energy band theory
NEXT STEPS
  • Research excitonic states in semiconductor physics
  • Explore the mechanisms of photoluminescence in direct band gap materials
  • Investigate shallow trap states and their impact on emission properties
  • Study the implications of near-band-edge emissions in optoelectronic devices
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Physicists, materials scientists, and engineers working in semiconductor technology and optoelectronics will benefit from this discussion, particularly those focused on photoluminescence and emission characteristics of materials.

maxxlr8
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I understand that in photoluminescence band edge emission in direct band gap semiconductors originates from the recombination of electron and hole in the edge of conduction and valence bands. However, recently I have stumbled upon near-band-edge emission, which seem to suggest the existence of other levels. My question is:
  1. Is the level in the forbidden band?
  2. How does this level exist?

Thank you
 
Physics news on Phys.org
Near band edge emission may arise essentially from excitonic or other shallow trap states
 

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