Left: Fabrication schematic for phosphor-free nanopyramid LEDs by nanospherical-lens photolithography. Right: (a) Room-temperature photoluminescence spectra of nanopyramid LEDs with MQWs grown at different temperatures, along with reference structure grown on planar template. (b) Spectrum of ‘white LED’ (blue LED with yellow phosphors). (c) Electroluminescence spectrum of nanopyramid LEDs at 20mA; inset shows corresponding optical microphotograph Home