Resonant-cavity light-emitting diodes: a review

2003; SPIE; Volume: 4996; Linguagem: Inglês

10.1117/12.476588

ISSN

1996-756X

Autores

Roel Baets, Danaë Delbeke, Ronny Bockstaele, Peter Bienstman,

Tópico(s)

Semiconductor Quantum Structures and Devices

Resumo

An overview of planar resonant-cavity light-emitting diodes is presented. Letting spontaneous emission happen in a planar cavity will in the first place affect the extraction efficiency. The internal intensity distribution is not longer isotropic due to interference effects (or density of states effects). The basics of dipole emission in planar cavities will be shortly reviewed using a classical approach valid in the so called weak-coupling regime. The total emission enhancement or Purcell factor, although small in planar cavities, will be explained. The design of a GaAs/AlGaAs RCLED is discussed. We review the state-of-the-art devices in different semiconductor material systems and at different wavelengths. Some advanced techniques based on gratings or photonic crystals to improve the efficiency of these devices are discussed. RCLEDs are not the only candidates that can be used as high-efficiency light sources in communication and non-communication applications. They compete with other high-efficiency LEDs and with VCSELs. The future prospects of RCLEDs are discussed in view of this competition.

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