Light Emitting Structures with Selective Carrier Injection Into Multiple Active Layers

Abstract

Disclosed herein are multi-layered optically active regions for semiconductor light-emitting devices (LEDs) that incorporate intermediate carrier blocking layers, the intermediate carrier blocking layers having design parameters for compositions and doping levels selected to provide efficient control over the carrier injection distribution across the active regions to achieve desired device injection characteristics. Examples of embodiments discussed herein include, among others: a multiple-quantum-well variable-color LED operating in visible optical range with full coverage of RGB gamut, a multiple-quantum-well variable-color LED operating in visible optical range with an extended color gamut beyond standard RGB gamut, a multiple-quantum-well light-white emitting LED with variable color temperature, and a multiple-quantum-well LED with uniformly populated active layers.

What is claimed is: 
     
         1 . A multi-layer semiconductor light emitting structure comprising:
 an optically active multi-layer region interposed between a pair of oppositely doped peripheral layers defining a structure junction, comprising:   a multiplicity of quantum confinement layers, each interposed between a pair of adjacent barrier layers and each having identical light emission wavelengths; and   a multiplicity of intermediate carrier blocking layers, each interposed between the respective adjacent barrier layers of the multiplicity of quantum confinement layers, each having conduction and valence band energies that are respectively higher and lower than the peripheral layers' or the barrier layers' respective band energy, each having a different band-gap with respect to each other, and each enabling a uniform charge carrier population into the multiplicity of quantum confinement layers at a specified current injection region.