Light emitting diodes include a substrate having first and second opposing faces and that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face. An optional \u03b4-layer of extremely high doping allows its threshold voltage to be set to a desired value. The width may be set to a predetermined maximum character width if all characters to be displayed will fit within the available space, or the width may be reduced to accommodate more characters.