270
12 Novel Nitride LED Technology
Fig. 12.14 Normalized PL spectra of CdSe-ZnSe quantum dots with different size (2.2, 2.7, 3.2,
3.4, 3.7, 3.8, 4.0, and 4.8 nm from left to right) [26]
12.3 Surface Plasmon Enhanced GaN-Based LED
Surface plasmon enhanced GaN-based LEDs are light-emitting devices that increase
internal quantum efficiency through the coupling of surface plasmon and electronhole pairs. The coupling is induced by the metal film or particles placed near the
light-emitting region. The metal film and particles can generate surface plasmons.
The coupling can increase the photon state density of the electron hole pair, thereby
increasing the radiation recombination rate and quantum efficiency of the electron
hole pair without changing the material properties and the band structure.
12.3.1 Basic Properties of Surface Plasmons
12.3.1.1 Surface Plasmon Polariton (SPP) and Localized Surface
Plasmon (LSP)
Surface plasmons are divided into two types: surface plasmon polariton (SPP) and
localized surface plasmon (LSP). SPP is the elementary excitations of surface electromagnetic wave propagating at the interface between the metal and the dielectric,
caused by the continuous longitudinal collective oscillation of electrons at the metal
boundary. The SPP field is mainly restrained within the region several nanometers away from the metal surface, which renders the surface plasmons some unique
12 Novel Nitride LED Technology
Fig. 12.14 Normalized PL spectra of CdSe-ZnSe quantum dots with different size (2.2, 2.7, 3.2,
3.4, 3.7, 3.8, 4.0, and 4.8 nm from left to right) [26]
12.3 Surface Plasmon Enhanced GaN-Based LED
Surface plasmon enhanced GaN-based LEDs are light-emitting devices that increase
internal quantum efficiency through the coupling of surface plasmon and electronhole pairs. The coupling is induced by the metal film or particles placed near the
light-emitting region. The metal film and particles can generate surface plasmons.
The coupling can increase the photon state density of the electron hole pair, thereby
increasing the radiation recombination rate and quantum efficiency of the electron
hole pair without changing the material properties and the band structure.
12.3.1 Basic Properties of Surface Plasmons
12.3.1.1 Surface Plasmon Polariton (SPP) and Localized Surface
Plasmon (LSP)
Surface plasmons are divided into two types: surface plasmon polariton (SPP) and
localized surface plasmon (LSP). SPP is the elementary excitations of surface electromagnetic wave propagating at the interface between the metal and the dielectric,
caused by the continuous longitudinal collective oscillation of electrons at the metal
boundary. The SPP field is mainly restrained within the region several nanometers away from the metal surface, which renders the surface plasmons some unique