A semiconductor-based light emitting platform (LEP) comprising a heated blackbody radiator wherein the light emitting platform is thermally isolated by nanowires having ultra-low thermal conductivity. In embodiments, the pixel is structured for broadband emission with a platform comprising an infrared surface structured for high emissivity within a broadband wavelength range. In other embodiments radiation is confined to a limited bandwidth by metamaterial and other resonant filters. In embodiments, the internal efficiency of the LEP configured for broadband operation can be higher compared with an LED.