High-quality bulk a-plane GaN sliced from boules in comparison to heteroepitaxially grown thick films on r-plane sapphire

  title={High-quality bulk a-plane GaN sliced from boules in comparison to heteroepitaxially grown thick films on r-plane sapphire},
  author={Tanja Paskova and Robert Kroeger and Stephan Figge and Detlef Hommel and Vanya Darakchieva and Bo Monemar and Edward Alfred Preble and Andrew D. Hanser and N. Mark Williams and M. Tutor},
  journal={Applied Physics Letters},
Thick GaN bars with [1120] orientation have been sliced from GaN boules grown on freestanding films by hydride vapor phase epitaxy (HVPE) in the [0001] direction. High-resolution x-ray diffraction and transmission electron microscopy have been used to study the structural quality and defect distribution in the material in comparison to heteroepitaxially grown thick HVPE-GaN films grown in the [1120] direction on (1102)-plane sapphire. It is demonstrated that while the heteroepitaxial material… 

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