TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The active layers and waveguiding layers comprise at least one indium gallium nitride quantum well with gallium nitride barrier layers and the cladding layers comprise at least one period of alternating aluminum gallium nitride layer (708) and gallium nitride layer (710). The substrate: is bulk III-nitride or a film of III-nitride; and comprises greater than or equal to 106 cm-2 threading dislocations.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The method further comprises growing the device layers on the vicinal surface, where an orientation of the vicinal surface is such that the device layers grow in a planar growth mode on the vicinal surface resulting in a planar top surface of the device layers. Preferred Components: In the substrate an orientation of the vicinal surface partially or fully compensates for the epilayer tilt and removes, minimizes or reduces slip related or shear stress related features from a top surface of the device layers. The epilayer tilt caused by the misfit dislocations is at least 0.5 degrees . The vicinal surface: is such that the top surface has a surface roughness of less than or equal to 0.4 nm over an area of at least 5/5 mu m of the top surface; is oriented or miscut with respect to an on-axis semi-polar plane of the substrate along a direction of at least one slip plane of the device layers so as to counter or reduce the epilayer tilt caused by the slip planes; is oriented or miscut at an angle with respect to a semipolar plane of the substrate and towards ac+ or c - direction of the substrate, where the angle is sufficiently small that the device layers grown on the substrate have a semipolar property that is characteristic of the semi-polar plane of the substrate, and where the angle is less than or equal to 5 degrees ; and is such that a top surface of the semi-polar III-nitride light emitting device structure emits the light with an emission that is uniform over an area of the top surface of at least 20/20 mu m. The device layers: form a semi-polar III-nitride light emitting device structure comprising a LED or laser diode (LD) device structure and include at least one light emitting active layer (702) that emits light having a peak intensity at a wavelength in a green wavelength range or longer or emit light having a peak intensity at a wavelength of greater than or equal to 500 nm and contain indium; further include waveguiding layers and cladding layers that are sufficiently thick and have a composition to function as waveguiding layers and cladding layers for the light emitted by the active layers of the LD or LED; are heterostructures or lattice mismatched with other layers of the device layers or the substrate or comprise a different composition from the other device layers or the substrate; comprise layers that are non-coherently grown or that are partially or fully relaxed; are thicker and higher composition alloy epilayers as compared to semi-polar III-nitride device layers that are grown on an on-axis surface of the semi-polar III-nitride substrate or semi-polar III-nitride device layers that are grown on a different vicinal surface of the semi-polar III-nitride substrate; and have a thickness and composition that is high enough such that a film comprising the device layers has a thickness near or greater than the film's critical thickness for relaxation. EXAMPLE - No suitable example given.