The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Indium, Gallium, or Indium and Gallium.

The method of claim 1, further comprising: repeating the steps (a)- (c) using the re-grown or coalesced second layer as the first layer in (a), wherein the segments comprise stripes; changing an orientation of the stripes of the layers in the subsequently deposited heterojunctions to obtain the 2-dimensional relaxation; and gradually increasing or decreasing the lattice constants of the layers in the subsequently deposited heterojunctions.

The method of claim 1, further comprising coalescing the segments with a coherently strained coalescence layer, wherein the coalescing is initiated by raising a temperature above a temperature used to grow the coherently strained coalescence layer prior to continuing the growth of the second layer.

The method of claim 1, further comprising: depositing mask material at a bottom or at a bottom and on a top of the segments to promote coalescence of the segments, and after the segments are merged, continuing growth of the second layer to overgrow masked areas masked by the mask material, thereby forming a continuous at least partially relaxed second layer, or interrupting the growth, removing the mask material on the top of the segments, and continuing the growth of the second layer afterwards.

The method of claim 1, wherein: the etching further comprises etching the coherently strained second layer into a pattern of stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and the re-growing of the second layer comprises: -3- G&C 30794.475-US-U l (i) growing a GaN coalescence layer under one dimensional (i D) tensile strain on top of the stripe pattern, adopting an a-lattice constant of the stripes in the stripe pattern, and (ii) growing an InGaN layer on the GaN coalescence layer, wherein the InGaN layer adopts the a-lattice constant of the stripes and results in 1D relaxation of the InGaN layer.

The method of claim 1, further comprising: growing the second layer as a coherently strained InGaN second layer, within critical thickness limits for the second layer, on the first layer comprising GaN; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of first stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and growing a first coalescence layer having a thickness of 20 nm or less and a different composition to the second layer, on top of the pattern _~is; patterning the first coalescence layer and the second layer into a pattern of second stripes with an angle between 30 and 90 degrees with respect to the first stripes in the second layer, resulting in formation of posts in the second layer and full or partial two dimensional relaxation of the second layer; coalescing the second stripes with a second coalescence layer having a thickness of 20 nm or less; and growing an InGaN layer on the second coalescence layer, wherein the InGaN layer adopts the lattice constant of the posts and has a different material composition to the second coalescence layer.

The method of claim 1, further comprising: -4- G&C 30794.475-US-U l growing the second layer as a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of the segments resulting in at least 1-dimensional or 2-dimensional partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and the continuing growth of, or th: re-growing of, the second layer, wherein the segments are merged or coalesced.

The method of claim 1, further comprising: growing the second layer comprising a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into ti segments resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and merging the segments by growing a coalescence layer composed of a material with a different composition than the coherently strained second layer.

The method of claim 1, wherein: the first layer comprises a Gallium Nitride layer; the growing and the forming of the second layer comprises: depositing a mask material on the Gallium Nitride layer, wherein the mask material includes openings having a width up to 1000 micrometers; and growing and forming the second layer comprising the relaxed I II -nitride pillar in each of a plurality of the openings, to form a plurality of the I II -nitride pillars, wherein the relaxed I II -nitride pillars include Indium or Gallium, or Indium and Gallium; and the continuing growth of the I II -nitride pillars includes the I II -nitride pillars overgrowing the openings to form the relaxed I II -nitride film including Indium and/or Gallium.

The method of claim 1, further comprising: growing the second layer comprising an InGaN bulk base layer; growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the InGaN active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer, and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer.

The method of claim 1, further comprising: growing the second layer comprising an n-type InGaN bulk base layer deposited on the first layer comprising a GaN substrate; and -7- G&C 30794.475-US-U l growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer; and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer; and (c) a p-type InGaN layer deposited on or above the InGaN active region.

The method of claim 1, wherein the second layer comprises one or more quantum wells.

The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Aluminum, Gallium, or Aluminum and Gallium.

The method of claim 14, wherein the pattern comprises first stripes oriented in a first direction, the method further comprising repeating steps (a)- (d) wherein: the In zGaiz N layer is the base layer for the next step (a); -6- G&C 30794.475-US-U l the strained In x Gai x N layer in the next step (b) is an InGai S N layer; the thicker In y Gai y N layer in the next step (b) is a In tGait N layer with s > t such that the In Gai S N layer and the In tGait N layer form a coherently strained stack; the etching in the next step (3) is with the pattern comprising second stripes oriented in a second direction; the In z Gai z N layer in the next growing step (d) is fully relaxed for y = t = z or partially relaxed in the presence of small differences between y, t, and z; and x, y, z, t are compositions of Indium in the InGaN layers.

The method of claim 14, wherein adjacent Iny Gai y N features in the stacks are merged by growth of the In z Gai z N, leading to a relaxed (z=y) or partially relaxed (z # y) In z Gai -z N film with a lattice constant corresponding to the patterned relaxed In y Gai y N features.

The method of claim 14, further comprising depositing the strained In XGa₁X N layer only in the nano or micron sized or width openings -8- G&C 30794.475-US-U l and/or selectively etching the thinner In xGaix N layer only.

The optoelectronic or electronic device of claim 27, further comprising a device structure grown on the InGaN bulk base layer, wherein: the device structure includes [[an]] tIe I nGaN active region having [[an]] t1 Indium composition of at least 25 %, and the InGaN bulk base

The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Indium, Gallium, or Indium and Gallium.

The method of claim 1, further comprising: repeating the steps (a)- (c) using the re-grown or coalesced second layer as the first layer in (a), wherein the segments comprise stripes; changing an orientation of the stripes of the layers in the subsequently deposited heterojunctions to obtain the 2-dimensional relaxation; and gradually increasing or decreasing the lattice constants of the layers in the subsequently deposited heterojunctions.

The method of claim 1, further comprising coalescing the segments with a coherently strained coalescence layer, wherein the coalescing is initiated by raising a temperature above a temperature used to grow the coherently strained coalescence layer prior to continuing the growth of the second layer.

The method of claim 1, further comprising: depositing mask material at a bottom or at a bottom and on a top of the segments to promote coalescence of the segments, and after the segments are merged, continuing growth of the second layer to overgrow masked areas masked by the mask material, thereby forming a continuous at least partially relaxed second layer, or interrupting the growth, removing the mask material on the top of the segments, and continuing the growth of the second layer afterwards.

The method of claim 1, wherein: the etching further comprises etching the coherently strained second layer into a pattern of stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and the re-growing of the second layer comprises: -3- G&C 30794.475-US-U l (i) growing a GaN coalescence layer under one dimensional (i D) tensile strain on top of the stripe pattern, adopting an a-lattice constant of the stripes in the stripe pattern, and (ii) growing an InGaN layer on the GaN coalescence layer, wherein the InGaN layer adopts the a-lattice constant of the stripes and results in 1D relaxation of the InGaN layer.

The method of claim 1, further comprising: growing the second layer as a coherently strained InGaN second layer, within critical thickness limits for the second layer, on the first layer comprising GaN; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of first stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and growing a first coalescence layer having a thickness of 20 nm or less and a different composition to the second layer, on top of the pattern _~is; patterning the first coalescence layer and the second layer into a pattern of second stripes with an angle between 30 and 90 degrees with respect to the first stripes in the second layer, resulting in formation of posts in the second layer and full or partial two dimensional relaxation of the second layer; coalescing the second stripes with a second coalescence layer having a thickness of 20 nm or less; and growing an InGaN layer on the second coalescence layer, wherein the InGaN layer adopts the lattice constant of the posts and has a different material composition to the second coalescence layer.

The method of claim 1, further comprising: -4- G&C 30794.475-US-U l growing the second layer as a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of the segments resulting in at least 1-dimensional or 2-dimensional partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and the continuing growth of, or th: re-growing of, the second layer, wherein the segments are merged or coalesced.

The method of claim 1, further comprising: growing the second layer comprising a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into ti segments resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and merging the segments by growing a coalescence layer composed of a material with a different composition than the coherently strained second layer.

The method of claim 1, wherein: the first layer comprises a Gallium Nitride layer; the growing and the forming of the second layer comprises: depositing a mask material on the Gallium Nitride layer, wherein the mask material includes openings having a width up to 1000 micrometers; and growing and forming the second layer comprising the relaxed I II -nitride pillar in each of a plurality of the openings, to form a plurality of the I II -nitride pillars, wherein the relaxed I II -nitride pillars include Indium or Gallium, or Indium and Gallium; and the continuing growth of the I II -nitride pillars includes the I II -nitride pillars overgrowing the openings to form the relaxed I II -nitride film including Indium and/or Gallium.

The method of claim 1, further comprising: growing the second layer comprising an InGaN bulk base layer; growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the InGaN active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer, and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer.

The method of claim 1, further comprising: growing the second layer comprising an n-type InGaN bulk base layer deposited on the first layer comprising a GaN substrate; and -7- G&C 30794.475-US-U l growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer; and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer; and (c) a p-type InGaN layer deposited on or above the InGaN active region.

The method of claim 1, wherein the second layer comprises one or more quantum wells.

The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Aluminum, Gallium, or Aluminum and Gallium.

The method of claim 14, wherein the pattern comprises first stripes oriented in a first direction, the method further comprising repeating steps (a)- (d) wherein: the In zGaiz N layer is the base layer for the next step (a); -6- G&C 30794.475-US-U l the strained In x Gai x N layer in the next step (b) is an InGai S N layer; the thicker In y Gai y N layer in the next step (b) is a In tGait N layer with s > t such that the In Gai S N layer and the In tGait N layer form a coherently strained stack; the etching in the next step (3) is with the pattern comprising second stripes oriented in a second direction; the In z Gai z N layer in the next growing step (d) is fully relaxed for y = t = z or partially relaxed in the presence of small differences between y, t, and z; and x, y, z, t are compositions of Indium in the InGaN layers.

The method of claim 14, wherein adjacent Iny Gai y N features in the stacks are merged by growth of the In z Gai z N, leading to a relaxed (z=y) or partially relaxed (z # y) In z Gai -z N film with a lattice constant corresponding to the patterned relaxed In y Gai y N features.

The method of claim 14, further comprising depositing the strained In XGa₁X N layer only in the nano or micron sized or width openings -8- G&C 30794.475-US-U l and/or selectively etching the thinner In xGaix N layer only.

The optoelectronic or electronic device of claim 27, further comprising a device structure grown on the InGaN bulk base layer, wherein: the device structure includes [[an]] tIe I nGaN active region having [[an]] t1 Indium composition of at least 25 %, and the InGaN bulk base

The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Indium, Gallium, or Indium and Gallium.

The method of claim 1, further comprising: repeating the steps (a)- (c) using the re-grown or coalesced second layer as the first layer in (a), wherein the segments comprise stripes; changing an orientation of the stripes of the layers in the subsequently deposited heterojunctions to obtain the 2-dimensional relaxation; and gradually increasing or decreasing the lattice constants of the layers in the subsequently deposited heterojunctions.

The method of claim 1, further comprising coalescing the segments with a coherently strained coalescence layer, wherein the coalescing is initiated by raising a temperature above a temperature used to grow the coherently strained coalescence layer prior to continuing the growth of the second layer.

The method of claim 1, further comprising: depositing mask material at a bottom or at a bottom and on a top of the segments to promote coalescence of the segments, and after the segments are merged, continuing growth of the second layer to overgrow masked areas masked by the mask material, thereby forming a continuous at least partially relaxed second layer, or interrupting the growth, removing the mask material on the top of the segments, and continuing the growth of the second layer afterwards.

The method of claim 1, wherein: the etching further comprises etching the coherently strained second layer into a pattern of stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and the re-growing of the second layer comprises: -3- G&C 30794.475-US-U l (i) growing a GaN coalescence layer under one dimensional (i D) tensile strain on top of the stripe pattern, adopting an a-lattice constant of the stripes in the stripe pattern, and (ii) growing an InGaN layer on the GaN coalescence layer, wherein the InGaN layer adopts the a-lattice constant of the stripes and results in 1D relaxation of the InGaN layer.

The method of claim 1, further comprising: growing the second layer as a coherently strained InGaN second layer, within critical thickness limits for the second layer, on the first layer comprising GaN; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of first stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and growing a first coalescence layer having a thickness of 20 nm or less and a different composition to the second layer, on top of the pattern _~is; patterning the first coalescence layer and the second layer into a pattern of second stripes with an angle between 30 and 90 degrees with respect to the first stripes in the second layer, resulting in formation of posts in the second layer and full or partial two dimensional relaxation of the second layer; coalescing the second stripes with a second coalescence layer having a thickness of 20 nm or less; and growing an InGaN layer on the second coalescence layer, wherein the InGaN layer adopts the lattice constant of the posts and has a different material composition to the second coalescence layer.

The method of claim 1, further comprising: -4- G&C 30794.475-US-U l growing the second layer as a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of the segments resulting in at least 1-dimensional or 2-dimensional partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and the continuing growth of, or th: re-growing of, the second layer, wherein the segments are merged or coalesced.

The method of claim 1, further comprising: growing the second layer comprising a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into ti segments resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and merging the segments by growing a coalescence layer composed of a material with a different composition than the coherently strained second layer.

The method of claim 1, wherein: the first layer comprises a Gallium Nitride layer; the growing and the forming of the second layer comprises: depositing a mask material on the Gallium Nitride layer, wherein the mask material includes openings having a width up to 1000 micrometers; and growing and forming the second layer comprising the relaxed I II -nitride pillar in each of a plurality of the openings, to form a plurality of the I II -nitride pillars, wherein the relaxed I II -nitride pillars include Indium or Gallium, or Indium and Gallium; and the continuing growth of the I II -nitride pillars includes the I II -nitride pillars overgrowing the openings to form the relaxed I II -nitride film including Indium and/or Gallium.

The method of claim 1, further comprising: growing the second layer comprising an InGaN bulk base layer; growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the InGaN active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer, and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer.

The method of claim 1, further comprising: growing the second layer comprising an n-type InGaN bulk base layer deposited on the first layer comprising a GaN substrate; and -7- G&C 30794.475-US-U l growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer; and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer; and (c) a p-type InGaN layer deposited on or above the InGaN active region.

The method of claim 1, wherein the second layer comprises one or more quantum wells.

The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Aluminum, Gallium, or Aluminum and Gallium.

The method of claim 14, wherein the pattern comprises first stripes oriented in a first direction, the method further comprising repeating steps (a)- (d) wherein: the In zGaiz N layer is the base layer for the next step (a); -6- G&C 30794.475-US-U l the strained In x Gai x N layer in the next step (b) is an InGai S N layer; the thicker In y Gai y N layer in the next step (b) is a In tGait N layer with s > t such that the In Gai S N layer and the In tGait N layer form a coherently strained stack; the etching in the next step (3) is with the pattern comprising second stripes oriented in a second direction; the In z Gai z N layer in the next growing step (d) is fully relaxed for y = t = z or partially relaxed in the presence of small differences between y, t, and z; and x, y, z, t are compositions of Indium in the InGaN layers.

The method of claim 14, wherein adjacent Iny Gai y N features in the stacks are merged by growth of the In z Gai z N, leading to a relaxed (z=y) or partially relaxed (z # y) In z Gai -z N film with a lattice constant corresponding to the patterned relaxed In y Gai y N features.

The method of claim 14, further comprising depositing the strained In XGa₁X N layer only in the nano or micron sized or width openings -8- G&C 30794.475-US-U l and/or selectively etching the thinner In xGaix N layer only.

The optoelectronic or electronic device of claim 27, further comprising a device structure grown on the InGaN bulk base layer, wherein: the device structure includes [[an]] tIe I nGaN active region having [[an]] t1 Indium composition of at least 25 %, and the InGaN bulk base

The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Indium, Gallium, or Indium and Gallium.

The method of claim 1, further comprising: repeating the steps (a)- (c) using the re-grown or coalesced second layer as the first layer in (a), wherein the segments comprise stripes; changing an orientation of the stripes of the layers in the subsequently deposited heterojunctions to obtain the 2-dimensional relaxation; and gradually increasing or decreasing the lattice constants of the layers in the subsequently deposited heterojunctions.

The method of claim 1, further comprising coalescing the segments with a coherently strained coalescence layer, wherein the coalescing is initiated by raising a temperature above a temperature used to grow the coherently strained coalescence layer prior to continuing the growth of the second layer.

The method of claim 1, further comprising: depositing mask material at a bottom or at a bottom and on a top of the segments to promote coalescence of the segments, and after the segments are merged, continuing growth of the second layer to overgrow masked areas masked by the mask material, thereby forming a continuous at least partially relaxed second layer, or interrupting the growth, removing the mask material on the top of the segments, and continuing the growth of the second layer afterwards.

The method of claim 1, wherein: the etching further comprises etching the coherently strained second layer into a pattern of stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and the re-growing of the second layer comprises: -3- G&C 30794.475-US-U l (i) growing a GaN coalescence layer under one dimensional (i D) tensile strain on top of the stripe pattern, adopting an a-lattice constant of the stripes in the stripe pattern, and (ii) growing an InGaN layer on the GaN coalescence layer, wherein the InGaN layer adopts the a-lattice constant of the stripes and results in 1D relaxation of the InGaN layer.

The method of claim 1, further comprising: growing the second layer as a coherently strained InGaN second layer, within critical thickness limits for the second layer, on the first layer comprising GaN; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of first stripes resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed stripes having up to a 1000 micrometer width; and growing a first coalescence layer having a thickness of 20 nm or less and a different composition to the second layer, on top of the pattern _~is; patterning the first coalescence layer and the second layer into a pattern of second stripes with an angle between 30 and 90 degrees with respect to the first stripes in the second layer, resulting in formation of posts in the second layer and full or partial two dimensional relaxation of the second layer; coalescing the second stripes with a second coalescence layer having a thickness of 20 nm or less; and growing an InGaN layer on the second coalescence layer, wherein the InGaN layer adopts the lattice constant of the posts and has a different material composition to the second coalescence layer.

The method of claim 1, further comprising: -4- G&C 30794.475-US-U l growing the second layer as a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into a pattern of the segments resulting in at least 1-dimensional or 2-dimensional partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and the continuing growth of, or th: re-growing of, the second layer, wherein the segments are merged or coalesced.

The method of claim 1, further comprising: growing the second layer comprising a coherently strained second layer, within critical thickness limits for the second layer; and forming the second layer, comprising: etching the coherently strained second layer into ti segments resulting in at least partial relaxation of the coherently strained second layer into at least partially relaxed segments having up to a 1000 micrometer width; and merging the segments by growing a coalescence layer composed of a material with a different composition than the coherently strained second layer.

The method of claim 1, wherein: the first layer comprises a Gallium Nitride layer; the growing and the forming of the second layer comprises: depositing a mask material on the Gallium Nitride layer, wherein the mask material includes openings having a width up to 1000 micrometers; and growing and forming the second layer comprising the relaxed I II -nitride pillar in each of a plurality of the openings, to form a plurality of the I II -nitride pillars, wherein the relaxed I II -nitride pillars include Indium or Gallium, or Indium and Gallium; and the continuing growth of the I II -nitride pillars includes the I II -nitride pillars overgrowing the openings to form the relaxed I II -nitride film including Indium and/or Gallium.

The method of claim 1, further comprising: growing the second layer comprising an InGaN bulk base layer; growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the InGaN active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer, and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer.

The method of claim 1, further comprising: growing the second layer comprising an n-type InGaN bulk base layer deposited on the first layer comprising a GaN substrate; and -7- G&C 30794.475-US-U l growing an InGaN active region coherently on or above the InGaN bulk base layer, wherein: (i) a thickness and Indium composition of the active region are larger than a thickness and Indium composition of an InGaN active region that is not grown on the InGaN bulk base layer; and (ii) the InGaN bulk base layer: (a) is at least partially relaxed, and (b) has one or more lattice constants that match one or more lattice constants of the InGaN active region grown on the InGaN bulk base layer; and (c) a p-type InGaN layer deposited on or above the InGaN active region.

The method of claim 1, wherein the second layer comprises one or more quantum wells.

The method of claim 1, wherein the first layer is GaN and the second layer is a nitride containing Aluminum, Gallium, or Aluminum and Gallium.

The method of claim 14, wherein the pattern comprises first stripes oriented in a first direction, the method further comprising repeating steps (a)- (d) wherein: the In zGaiz N layer is the base layer for the next step (a); -6- G&C 30794.475-US-U l the strained In x Gai x N layer in the next step (b) is an InGai S N layer; the thicker In y Gai y N layer in the next step (b) is a In tGait N layer with s > t such that the In Gai S N layer and the In tGait N layer form a coherently strained stack; the etching in the next step (3) is with the pattern comprising second stripes oriented in a second direction; the In z Gai z N layer in the next growing step (d) is fully relaxed for y = t = z or partially relaxed in the presence of small differences between y, t, and z; and x, y, z, t are compositions of Indium in the InGaN layers.

The method of claim 14, wherein adjacent Iny Gai y N features in the stacks are merged by growth of the In z Gai z N, leading to a relaxed (z=y) or partially relaxed (z # y) In z Gai -z N film with a lattice constant corresponding to the patterned relaxed In y Gai y N features.

The method of claim 14, further comprising depositing the strained In XGa₁X N layer only in the nano or micron sized or width openings -8- G&C 30794.475-US-U l and/or selectively etching the thinner In xGaix N layer only.

The optoelectronic or electronic device of claim 27, further comprising a device structure grown on the InGaN bulk base layer, wherein: the device structure includes [[an]] tIe I nGaN active region having [[an]] t1 Indium composition of at least 25 %, and the InGaN bulk base