NOVELTY - The photoactive device comprises a volume of strain relaxed indium gallium nitride semiconductor material, a first base region comprising a III-nitride semiconductor material disposed over the volume of strain relaxed indium gallium nitride semiconductor material, a second base region comprising a III-nitride semiconductor material, and a multi-quantum well structure disposed between the first and second base regions. An electron hole energy barrier between third and second quantum well regions is less than an electron hole energy barrier between second and first quantum well regions.    USE - Used as a photoactive device such as a LED, a semiconductor laser, a photodetector and a solar cell.    ADVANTAGE - The photoactive device can be efficiently manufactured with improved distribution of charge carriers and operational performance and without point and line defects such as threading dislocations.    DETAILED DESCRIPTION - The photoactive device comprises a volume of strain relaxed indium gallium nitride semiconductor material, a first base region comprising a III-nitride semiconductor material disposed over the volume of strain relaxed indium gallium nitride semiconductor material, a second base region comprising a III-nitride semiconductor material, and a multi-quantum well structure disposed between the first base region and the second base region. The multi-quantum well structure comprises quantum well regions and barrier regions, where a first barrier region is disposed between a first quantum well region and a second quantum well region and a second barrier region is between the second quantum well region and a third quantum well region. The first quantum well region is located closer to the first base region than the third quantum well region, and the third quantum well region is located closer to the second base region than the first quantum well region. An electron hole energy barrier between the third quantum well region and the second quantum well region is less than an electron hole energy barrier between the second quantum well region and the first quantum well region. The multi-quantum well structure has a total thickness in a direction extending between the first base region and the second base region of 85 nm. The multi-quantum well structure has a total thickness, which is less than its critical thickness, in a direction extending between the first base region and the second base region. Each of the first and second barrier regions has a barrier region thickness, which is greater than each of the well region thicknesses, in a direction extending between the first base region and the second base region. The electron holes are evenly distributed across the multi-quantum well structure. An INDEPENDENT CLAIM is included for a method of forming a photoactive device.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a method for forming a radiation-emitting semiconductor device.    Substrate (152)    Strain relaxation layer (154)    Base substrate (156)    Layer of strained semiconductor material. (158)