A light emitting device, comprising: a III-nitride semiconductor structure including an active region disposed between a first layer of first conductivity type and a first layer of second conductivity type; a tunnel junction on the first layer of second conductivity type, the tunnel junction comprising: a second layer of second conductivity type, which is a highly doped p-type layer, on the first layer of second conductivity type, said second layer of second conductivity type having a dopant concentration greater than the first layer of second conductivity type; and a second layer of first conductivity type, which is a highly doped n-type layer, on the second layer of second conductivity type, said second layer of first conductivity type having a dopant concentration greater than the first layer of first conductivity type; and a third layer of first conductivity type on the tunnel junction; wherein a thickness of the third layer of first conductivity type varies periodically, wherein a photonic crystal structure consists of a periodic variation in a thickness of the third layer; wherein the tunnel junction is between the first layer of first conductivity type and the third layer of first conductivity type, wherein the first conductivity type is n-type and wherein the second conductivity is p-type. a III-nitride semiconductor structure including an active region disposed between a first layer of first conductivity type and a first layer of second conductivity type; a tunnel junction on the first layer of second conductivity type, the tunnel junction comprising: a second layer of second conductivity type, which is a highly doped p-type layer, on the first layer of second conductivity type, said second layer of second conductivity type having a dopant concentration greater than the first layer of second conductivity type; and a second layer of first conductivity type, which is a highly doped n-type layer, on the second layer of second conductivity type, said second layer of first conductivity type having a dopant concentration greater than the first layer of first conductivity type; and a third layer of first conductivity type on the tunnel junction; wherein a thickness of the third layer of first conductivity type varies periodically, wherein a photonic crystal structure consists of a periodic variation in a thickness of the third layer; wherein the tunnel junction is between the first layer of first conductivity type and the third layer of first conductivity type, wherein the first conductivity type is n-type and wherein the second conductivity is p-type. a second layer of second conductivity type, which is a highly doped p-type layer, on the first layer of second conductivity type, said second layer of second conductivity type having a dopant concentration greater than the first layer of second conductivity type; and a second layer of first conductivity type, which is a highly doped n-type layer, on the second layer of second conductivity type, said second layer of first conductivity type having a dopant concentration greater than the first layer of first conductivity type; and a third layer of first conductivity type on the tunnel junction; wherein a thickness of the third layer of first conductivity type varies periodically, wherein a photonic crystal structure consists of a periodic variation in a thickness of the third layer; wherein the tunnel junction is between the first layer of first conductivity type and the third layer of first conductivity type, wherein the first conductivity type is n-type and wherein the second conductivity is p-type.