A monolithic nonphosphor broadband-emission light-emitting diode is demonstrated, comprising a combination of high-density microstructured and nanostructured InGaN-GaN quantum wells fabricated using a top-down approach. Broadband emission is achieved by taking advantage of low-dimensional-induced strain-relaxation of highly strained quantum wells, combining light emitted from strain-relaxed nanotips at wavelengths shorter than the as-grown by as much as 80 nm with longer-wavelength light emitted from the larger nonrelaxed microdisks. The localized emission characteristics have been studied by spatially resolved near-field photoluminescence spectroscopy which enabled both the photoluminescence intensity and spectrum from individual nanotips to be distinguished from emission at the larger-dimensioned regions. Distinctive blue-green-yellow emission can be observed from the electroluminescent device, whose continuous broadband spectrum is characterized by CIE coordinates of (0.39, 0.47) and color rendering in...