Showing papers by "Stacia Keller published in 1995"
TL;DR: The structural evolution of epitaxial GaN layers grown on basal plane sapphire has been studied by atomic force microscopy, x-ray diffraction, and transmission electron microscopy (TEM).
Abstract: The structural evolution of epitaxial GaN layers grown on basal plane sapphire has been studied by atomic force microscopy (AFM), x‐ray diffraction, and transmission electron microscopy (TEM). High‐temperature growth (1050–1080 °C) on optimized nucleation layers leads to clear, specular films. AFM on the as‐grown surface shows evenly spaced monatomic steps indicative of layer by layer growth. AFM measurements show a step termination density of 1.7×108 cm−2 for 5 μm films. This value is in close agreement with TEM measurements of screw and mixed screw‐edge threading dislocation density. The total measured threading dislocation density in the 5 μm films is 7×108 cm−2.
313 citations
TL;DR: In this article, the first lasing operation was realized for InGaAlP visible lasers grown by metal organic chemical vapor deposition (MOCVD) with TBP which is a liquid organometallic source, a safer alternative to phosphine.
Abstract: The first lasing operation was realized for InGaAlP visible lasers grown by metal organic chemical vapor deposition (MOCVD) with TBP which is a liquid organometallic source, a safer alternative to phosphine. A threshold current density was 1.3 kA/cm2 with pulse operation was obtained for broad area lasers at 77 K. The threshold current density was observed to be extremely sensitive to the temperature even at low temperature region, which is considered to be caused by a higher non-radiative recombination rate in the cladding layers.
5 citations