Applied Physics Letters · 2001 · 40 citations · 24 references
EngineeringMaterials EngineeringMaterials ScienceOptical MaterialsOptoelectronicsSemiconductor MaterialsEpitaxial GrowthLuminescent MaterialsOptical Properties Of SemiconductorsSemiconductor Crystal GrowthSemiconductor PhysicsWide Band Gap SemiconductorsCrystalline StructureGallium NitrideGallium Nitride (Gan) MaterialsHydride Vapor Phase EpitaxyMetal-organic Chemical Vapor DepositionMetalorganic Chemical Vapor DepositionOptical PropertiesPhotoluminescence Spectroscopy
High-quality free-standing GaN was obtained by hydride vapor-phase epitaxy (HVPE) growth and the subsequent removal of the sapphire substrates. In the photoluminescence (PL) spectra of the as-grown HVPE-GaN, we observed a strong phonon replica peak for temperatures higher than 80 K. Both the near-band-edge emission and the yellow emission in the cathodoluminescence spectra were inhomogeneous, and correlated with the crystalline structure. With the homoepitaxial regrowth by metal–organic chemical-vapor deposition (MOCVD) in the GaN substrates, these unusual optical properties were no longer observed and the PL peak became sharper than GaN grown by MOCVD on sapphire substrates, indicating that the free-standing GaN is suitable as substrates for the growth of device structures.
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Shuji Nakamura, Masayuki Senoh, Shin‐ichi Nagahama et al. · Applied Physics Letters · 1998 · 732 citations
Absorption, Reflectance, and Luminescence of GaN Epitaxial Layers
R. Dingle, D. D. Sell, S. E. Stokowski et al. · Physical review. B, Solid state · 1971 · 526 citations