# US 2018/0323340 A1 · White Light Emitting Structures with Controllable Emission Color Temperature > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323340 A1 - Document ID: US20180323340A1 - Status: Published application - Kind: A1 - Application number: 15/990,494 - Filed: 2018-05-25 - Published: 2018-11-08 - Earliest claimed: 2015-06-05 - Assignees: Ostendo Technologies, Inc. - Applicants: Ostendo Technologies, Inc. - Inventors: Hussein S. El-Ghoroury; Mikhail V. Kisin; Yea-Chuan Milton Yeh; Chih-Li Chuang; Jyh-Chia Chen - Web page: https://patentgrep.com/patent/US20180323340A1 ## CPC - H10H 20/813: having a plurality of light-emitting regions, e.g. multi-junction LEDs or light-emitting devices having photoluminescent regions within the bodies - H01S 5/0421: {characterised by the semiconducting contacting layers (electrodes H01S5/0425)} - H01S 5/0622: {Controlling the frequency of the radiation} - H01S 5/34333: {with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser} - H10H 20/812: within the light-emitting regions, e.g. having quantum confinement structures - H10H 20/825: containing nitrogen, e.g. GaN - H01S 5/1096: {in a single cavity} - H01S 5/2009: {by using electron barrier layers} - H01S 5/3407: {characterised by special barrier layers} - H01S 5/4043: {with vertically stacked active layers} - H01S 5/4093: {Red, green and blue [RGB] generated directly by laser action or by a combination of laser action with nonlinear frequency conversion} - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## 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. ## Claims ### Claim 1 A multi-layer semiconductor light emitting structure comprising: a first quantum confinement structure for emitting light of a first wavelength; a first intermediate carrier blocking layer; a second quantum confinement structure for emitting light of a second wavelength, wherein the first intermediate carrier blocking layer is disposed between the first quantum confinement structure and the second quantum confinement structure and the first intermediate carrier blocking layer comprises a composition that is undoped or doped of a single conductivity type to provide a first predetermined band-gap and band-offsets relative to each of the first quantum confinement structure and the second quantum confinement structure; a second intermediate carrier blocking layer ; a third quantum confinement structure for emitting light of a third wavelength, wherein the second intermediate carrier blocking layer is disposed between the second quantum confinement structure and the third quantum confinement structure and the second intermediate carrier blocking layer comprises a composition that is undoped or doped of a single conductivity type to provide a second predetermined band-gap and band-offsets relative to each of the second quantum confinement structure and the third quantum confinement structure; and the first, second and third quantum confinement structures emitting primary colors of red, green and blue respectively, wherein the band-gaps and the band-offsets of the first and second intermediate carrier blocking layers are selected to cause the first, second and third quantum confinement structures to emit light of the respective wavelength and with a relative intensity contribution to cause the multi-layer semiconductor light emitting structure to emit white light. ### Claim 2 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1, wherein only one of the composition of the first intermediate carrier blocking layer and the composition of the second intermediate carrier blocking layer is doped and the other is undoped. ### Claim 3 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1 wherein at least one of the first and second quantum confinement structures comprises a quantum wire. ### Claim 4 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1 wherein at least one of the first and second quantum confinement structures comprises a quantum dot. ### Claim 5 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1 wherein at least one of the first and second quantum confinement structures comprises a quantum well. ### Claim 6 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1 wherein at least one of the first, second and third quantum confinement structures comprises multiple quantum wells. ### Claim 7 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1 wherein the first, second and third quantum confinement structures emit the respective colors with approximately equal CIE at an injection current density of approximately 50 A/cm2. ### Claim 8 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1 wherein the first, second and third quantum confinement structures emit red, green and blue light with approximately equal CIE emissions for a particular injection current density, and when the particular injection current density increases, the blue emission increases and the green emission decreases. ### Claim 9 (depends on 8) The multi-layer semiconductor light emitting structure of claim 8 wherein an emission color temperature of the white-light-emitting device is controllable by controlling the injection current density. ### Claim 10 (depends on 8) The multi-layer semiconductor light emitting structure of claim 8 wherein the first, second and third quantum confinement structures emit the respective colors with approximately equal CIE emissions when the red emission is also decreasing with increasing injection current density. ### Claim 11 (depends on 10) The multi-layer semiconductor light emitting structure of claim 10 wherein the emission color temperature of the multi-layer semiconductor light emitting structure emitting white light is controllable by controlling the injection current density. ### Claim 12 (depends on 1) The multi-layer semiconductor light emitting structure of claim 1, wherein the first, second and third quantum confinement structures are disposed between an n-doped layer and a p-doped layer and the multi-layer semiconductor light emitting structure further comprises a first contact coupled to the n-doped layer and a second contact coupled to the p-doped layer, and wherein a carrier injection into each of the first, second and third quantum confinement structures is achieved through the first contact and the second contact. ### Claim 13 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. ### Claim 14 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13 wherein at least one of the first and second quantum confinement structures comprises a quantum wire. ### Claim 15 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13 wherein at least one of the first and second quantum confinement structures comprises a quantum dot. ### Claim 16 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13 wherein at least one of the first and second quantum confinement structures comprises a quantum well. ### Claim 17 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13 wherein at least one of the first, second and third quantum confinement structures comprises multiple quantum wells. ### Claim 18 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13 wherein the first, second and third quantum confinement structures emit the respective colors with approximately equal CIE at an injection current density of approximately 50 A/cm2. ### Claim 19 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13 wherein the first, second and third quantum confinement structures emit red, green and blue light with approximately equal CIE emissions for a particular injection current density, and when the particular injection current density increases, the blue emission increases and the green emission decreases. ### Claim 20 (depends on 19) The multi-layer semiconductor light emitting structure of claim 19 wherein an emission color temperature of the white-light-emitting device is controllable by controlling the injection current density. ### Claim 21 (depends on 19) The multi-layer semiconductor light emitting structure of claim 19 wherein the first, second and third quantum confinement structures emit the respective colors with approximately equal CIE emissions when the red emission is also decreasing with increasing injection current density. ### Claim 22 (depends on 21) The multi-layer semiconductor light emitting structure of claim 21 wherein the emission color temperature of the multi-layer semiconductor light emitting structure emitting white light is controllable by controlling the injection current density. ### Claim 23 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13, wherein the first, second and third quantum confinement structures are disposed between an n-doped layer and a p-doped layer and the multi-layer semiconductor light emitting structure further comprises a first contact coupled to the n-doped layer and a second contact coupled to the p-doped layer, and wherein a carrier injection into each of the first, second and third quantum confinement structures is achieved through the first contact and the second contact. ### Claim 24 (depends on 13) The multi-layer semiconductor light emitting structure of claim 13, wherein only one of the composition of the first intermediate carrier blocking layer and the composition of the second intermediate carrier blocking layer is doped and the other is undoped.