Growth and fabrication of semi-polar InGaN/GaN multi-quantum well light-emitting diodes on microstructured Si (001) substrates

Semi-polar (1-101) InGaN/GaN light-emitting diodes were prepared on standard electronic-grade Si (100) substrates. Micro-stripes of GaN and InGaN/GaN quantum wells on semi-polar facets were grown on intersecting 111 planes of microscale V-grooved Si in metal-organic vapor phase epitaxy, covering over 50% of the wafer surface area. In-situ optical reflectivity and curvature measurements demonstrate that the effect of the thermal expansion coefficient mismatch was greatly reduced. A cross-sectional analysis reveals low threading dislocation density on the top of most surfaces. On such prepared (1-101) GaN, an InGaN/GaN LED was fabricated. Electroluminescence over 5 mA to 60 mA is found with a much lower blue-shift than that on the c-plane device. Such structures therefore could allow higher efficiency light emitters with a weak quantum confined Stark effect throughout the visible spectrum.