III-nitride light emitting device with double heterostructure light emitting region

Abstract

A III-nitride light emitting layer is disposed between an n-type region and a p-type region. The light emitting layer is a doped thick layer. In some embodiments, the light emitting layer is sandwiched between two doped spacer layers.

1 . A semiconductor light emitting device comprising: 
 an n-type region;    a p-type region; and    a III-nitride light emitting layer disposed between the n-type region and the p-type region, wherein: 
 the III-nitride light emitting layer is doped to a dopant concentration between 6×10 18  cm −3  and 5×10 19  cm −3 ;  
 the III-nitride light emitting layer has a thickness between 50 Å and 250 Å; and  
 the III-nitride light emitting layer is configured to emit light having a peak wavelength greater than 390 nm.  
   
     
     
         2 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer is InGaN.  
     
     
         3 . The semiconductor light emitting device of  claim 2  wherein a composition of InN in the light emitting layer is graded.  
     
     
         4 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer is AlInGaN.  
     
     
         5 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a concentration of threading dislocations less than 10 9 /cm 2 .  
     
     
         6 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a concentration of threading dislocations less than 10 8 /cm 2 .  
     
     
         7 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a concentration of threading dislocations less than 10 7 /cm 2 .  
     
     
         8 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a concentration of threading dislocations less than 10 6 /cm 2 .  
     
     
         9 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a graded dopant concentration.  
     
     
         10 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a dopant concentration between 1×10 19  cm −3  and 5×10 19  cm −3 .  
     
     
         11 . The semiconductor light emitting device of  claim 10  wherein the light emitting layer is configured to emit light having a peak wavelength between 440 nm and 460 nm.  
     
     
         12 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a dopant concentration between 6×10 8  cm −3  and 2×10 9  cm −3 .  
     
     
         13 . The semiconductor light emitting device of  claim 12  wherein the light emitting layer is configured to emit light having a peak wavelength between 420 nm and 440 nm.  
     
     
         14 . The semiconductor light emitting device of  claim 1  wherein the light emitting layer has a thickness between 75 Å and 150 Å.  
     
     
         15 . The semiconductor light emitting device of  claim 1  further comprising: 
 a first spacer layer disposed between the n-type region and the III-nitride light emitting layer, the first spacer layer being in direct contact with the III-nitride light emitting layer; and    a second spacer layer disposed between the p-type region and the III-nitride light emitting layer, the second spacer layer being in direct contact with the III-nitride light emitting layer;    wherein each of the first and second spacer layers are not intentionally doped or doped to a dopant concentration less than 6×10 18  cm −3 .    
     
     
         16 . The semiconductor light emitting device of  claim 1  wherein the III-nitride light emitting layer is doped n-type with Si.  
     
     
         17 . The semiconductor light emitting device of  claim 1  wherein the III-nitride light emitting layer is doped with a single dopant species.  
     
     
         18 . The semiconductor light emitting device of  claim 1  further comprising an InGaN preparation layer disposed between the n-type region and the III-nitride light emitting layer.  
     
     
         19 . The semiconductor light emitting device of  claim 1  further comprising a blocking layer disposed between the p-type region and the III-nitride light emitting layer, the blocking layer having a band gap greater than 3.5 eV.  
     
     
         20 . A semiconductor light emitting device comprising: 
 an n-type region;    a p-type region;    a III-nitride light emitting layer disposed between the n-type region and the p-type region, the III-nitride light emitting layer being doped to a dopant concentration between 6×10 18  cm −3  and 5×10 19  cm −3 , the III-nitride light emitting layer having a thickness between 50 Å and 600 Å, and the III-nitride light emitting layer being configured to emit light having a peak wavelength greater than 390 nm;    a first spacer layer disposed between the n-type region and the III-nitride light emitting layer, the first spacer layer being in direct contact with the III-nitride light emitting layer; and    a second spacer layer disposed between the p-type region and the III-nitride light emitting layer, the second spacer layer being in direct contact with the III-nitride light emitting layer;    wherein one of the first and the second spacer layers is doped to a dopant concentration between 6×10 18  cm −3  and 5×10 19  cm −3 .    
     
     
         21 . The semiconductor light emitting device of  claim 20  wherein: 
 the first spacer layer is doped to a dopant concentration between 6×10 18  cm −3  and 5×10 19  cm −3 ; and    the second spacer layer is not intentionally doped or doped to a dopant concentration less than 6×10 18  cm −3 .    
     
     
         22 . The semiconductor light emitting device of  claim 20  wherein: 
 the first spacer layer is not intentionally doped or doped to a dopant concentration less than 6×10 18  cm −3 ; and    the second spacer layer is doped to a dopant concentration between 6×10 18  cm −3  and 5×10 19  cm −3 .    
     
     
         23 . The semiconductor light emitting device of  claim 20  wherein the III-nitride light emitting layer is InGaN.  
     
     
         24 . The semiconductor light emitting device of  claim 23  wherein a composition of InN in the light emitting layer is graded.  
     
     
         25 . The semiconductor light emitting device of  claim 20  wherein the first and second spacer layers each have a thickness between 20 Å and 1000 Å.  
     
     
         26 . The semiconductor light emitting device of  claim 20  wherein the first and second spacer layers are both GaN.  
     
     
         27 . The semiconductor light emitting device of  claim 20  wherein the light emitting layer is AlInGaN.  
     
     
         28 . The semiconductor light emitting device of  claim 20  further comprising: 
 contacts electrically connected to the n-type region and the p-type region.    
     
     
         29 . The semiconductor light emitting device of  claim 20  wherein one of the first and second spacer layers has a graded dopant concentration.  
     
     
         30 . The semiconductor light emitting device of  claim 20  wherein a portion of the n-type region is doped to a dopant concentration substantially the same as the dopant concentration in the light emitting layer.  
     
     
         31 . The semiconductor light emitting device of  claim 20  further comprising an InGaN preparation layer disposed between the n-type region and the III-nitride light emitting layer.  
     
     
         32 . The semiconductor light emitting device of  claim 20  further comprising a blocking layer disposed between the p-type region and the III-nitride light emitting layer, the blocking layer having a band gap greater than 3.5 eV.  
     
     
         33 . A semiconductor light emitting device comprising: 
 an n-type region;    a p-type region;    a III-nitride light emitting layer disposed between the n-type region and the p-type region, wherein: 
 the III-nitride light emitting layer has a thickness between 50 Å and 600 Å; and  
 the III-nitride light emitting layer is configured to emit light having a peak wavelength greater than 390 nm; and  
   a blocking layer disposed between the p-type region and the III-nitride light emitting layer, the blocking layer having a band gap greater than 3.5 eV.    
     
     
         34 . The semiconductor light emitting device of  claim 33  wherein a ratio of photons extracted from the device to current supplied to the device when 200 A/cm 2  is supplied to the device is greater than a ratio of photons extracted from the device to current supplied to the device when 20 A/cm 2  is supplied to the device.  
     
     
         35 . The semiconductor light emitting device of  claim 33  wherein the light emitting layer is InGaN.  
     
     
         36 . The semiconductor light emitting device of  claim 35  wherein a composition of InN in the light emitting layer is graded.  
     
     
         37 . The semiconductor light emitting device of  claim 33  wherein the blocking layer is AlGaN.  
     
     
         38 . The semiconductor light emitting device of  claim 37  wherein the blocking layer has an AlN composition between 8% and 30%.  
     
     
         39 . The semiconductor light emitting device of  claim 33  wherein a difference between a peak wavelength of light emitted by the light emitting layer when 930 A/cm 2  is supplied to the device and a peak wavelength of light emitted by the light emitting layer when 20 A/cm 2  is supplied to the device is less than 5 nm.  
     
     
         40 . The semiconductor light emitting device of  claim 33  wherein a difference between a peak wavelength of light emitted by the light emitting layer when 200 A/cm 2  is supplied to the device and a peak wavelength of light emitted by the light emitting layer when 20 A/cm 2  is supplied to the device is less than 3 nm.  
     
     
         41 . The semiconductor light emitting device of  claim 33  further comprising an InGaN preparation layer disposed between the n-type region and the III-nitride light emitting layer.  
     
     
         42 . A semiconductor light emitting device comprising: 
 an n-type region;    a p-type region;    a III-nitride light emitting layer disposed between the n-type region and the p-type region, wherein: 
 the III-nitride light emitting layer has a thickness between 50 Å and 600 Å; and  
 the III-nitride light emitting layer is configured to emit light having a peak wavelength greater than 390 nm; and  
   an InGaN preparation layer disposed between the n-type region and the III-nitride light emitting layer.    
     
     
         43 . The semiconductor light emitting device of  claim 42  wherein the III-nitride light emitting layer is InGaN.  
     
     
         44 . The semiconductor light emitting device of  claim 43  wherein a composition of InN in the light emitting layer is graded.  
     
     
         45 . The semiconductor light emitting device of  claim 42  wherein the preparation layer has an InN composition between 2% and 12%.  
     
     
         46 . The semiconductor light emitting device of  claim 42  wherein the preparation layer has an InN composition between 2% and 6%.  
     
     
         47 . A semiconductor light emitting device comprising: 
 an n-type region;    a p-type region;    a III-nitride light emitting layer disposed between the n-type region and the p-type region, the III-nitride light emitting layer a thickness between 50 Å and 600 Å, the III-nitride light emitting layer being not intentionally doped or doped to a dopant concentration less than 6×10 8  cm −3 ;    a first spacer layer disposed between the n-type region and the III-nitride light emitting layer, the first spacer layer being in direct contact with the III-nitride light emitting layer; and    a second spacer layer disposed between the p-type region and the III-nitride light emitting layer, the second spacer layer being in direct contact with the III-nitride light emitting layer; wherein: 
 each of the first and the second spacer layers is doped to a dopant concentration between 6×10 18  cm −3  and 5×10 19  cm 3 ; and  
 the first and the second spacer layers are doped with dopants of the same conductivity type.