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Communications at congresses:
Cathodoluminescence study of ZnO wafers cut from hydrothermal crystals.
Research Areas
  • Electronics engineering
ZnO is a promising wide bandgap semiconductor for UV optoelectronics. Room temperature ZnO based light emitting devices have been recently demonstrated. One of the main potential advantages of ZnO respect to its competitor GaN is the availability of large crystals to be used as substrates for homoepitaxial growth. High quality ZnO wafers are expected to boost the progress of the commercial ZnO based devices. However, ZnO wafers machined from ZnO crystals are not yet satisfactory for homoepitaxial growth; therefore, other alternative substrates are still preferred. Nevertheless, the achievement of high quality ZnO wafers is necessary for the breakthrough of high power ZnO based devices. In spite of the progress achieved in ZnO crystal growth, many issues remain open to improve the wafer quality for homoepitaxial growth. Luminescence spectroscopy is a powerful technique to study the substrate quality, since it is sensitive to the presence of defects. One of the main issues concerning ZnO wafers for homoepitaxial growth concerns the mechanical damages induced by polishing. Also the reactivity of the surface is a key issue. To overcome these problems one needs to understand the role played by native defects and impurities, and how they interact in the presence of mechanical damage, and thermal treatments. Cathodoluminescence is a very powerful tool to study these wafers, because it adds to the luminescence spectroscopy capacity the modulation of the probe depth by varying the energy of the e-beam electrons. We present herein a CL study of different ZnO wafers cut from hydrothermal ZnO crystals; the main spectral issues concerning the wafer quality are discussed, aiming to establish criteria for wafer quality. The influence of mechanical damage and thermal treatments are also discussed.
European Research Society 2007 Spring Meeting
Estrasburgo, Francia
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  • Participante: Buguo Wang
  • Participante: M Callahan
  • Participante: M Avella (Universidad de Valladolid)
  • Autor: Tomas Rodriguez Rodriguez (UPM)
  • Participante: D Bliss
  • Participante: J Mass
  • Autor: Andres Rodriguez Dominguez (UPM)
  • Participante: Juan Jiménez (Universidad de Valladolid)
Research Group, Departaments and Institutes related
  • Creador: Departamento: Tecnología Electrónica
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