White Light Emitting Structures with Controllable Emission Color Temperature

A multi-layer semiconductor light emitting structure comprising:

• a first quantum confinement structure for emitting light of a first wavelength, the first quantum confinement structure comprising at least one first optically active layer disposed between barrier layers;
• a first intermediate carrier blocking layer;
• a second quantum confinement structure for emitting light of a second wavelength, the second quantum confinement structure comprising at least one second optically active layer disposed between barrier layers;
• a second intermediate carrier blocking layer;
• and
• a third quantum confinement structure for emitting light of a third wavelength, the third quantum confinement structure comprising at least one third optically active layer disposed between barrier layers,
• wherein the first intermediate carrier blocking layer is disposed between the first quantum confinement structure and the second quantum confinement structure and adjacent to a barrier layer of the first quantum confinement structure and adjacent to a barrier layer of the second quantum confinement structure and wherein the first intermediate carrier blocking layer comprises (1) a first band-gap greater than a band-gap of the adjacent barrier layer of the first quantum confinement structure and greater than a band-gap of the adjacent barrier layer of the second quantum confinement structure and (2) band-offsets relative to energy bands of the adjacent barrier layer of the first quantum confinement structure and relative to energy bands of the adjacent barrier layer of the second quantum confinement structure,
• wherein the second intermediate carrier blocking layer is disposed between a barrier layer of the second quantum confinement structure and a barrier layer of the third quantum confinement structure and adjacent to a barrier layer of the second quantum confinement structure and adjacent to a barrier layer of the third quantum confinement structure and wherein the second intermediate carrier blocking layer comprises (1) a second band-gap greater than a band-gap of the adjacent barrier layer of the second quantum confinement structure and greater than a band-gap of the adjacent barrier layer of the third quantum confinement structure and (2) band-offsets relative to energy bands of the adjacent barrier layer of the second quantum confinement structure and relative to energy bands of the adjacent barrier layer of the third quantum confinement structure,
• wherein the first, second and third quantum confinement structures emitting primary colors of red, green and blue, respectively, and
• wherein the first and second intermediate carrier blocking layers each comprise a composition that is undoped or doped of a single conductivity type to provide the first and second band-gaps and band-offsets selected to cause the first, second and third quantum confinement structures to emit light of the primary colors with a relative intensity to form white light.