Abstract:

Between n- GaN and p- AlGaN+GaN contacts, the blue light emitting diode (LED) structure with InGaN/GaN multiple quantum well has been grown using metalorganic vapor phase epitax (MOCVD) on c-oriented sapphire substrate. In order to research the strain and the stress of the lattice in crystal form, a reciprocal lattice space was mapped using a High Resolution X-Ray Diffractometer. In this study, by taking the qualities of the GaN epitaxial structure as reference point; relaxation, strain, hydrostatical strain and biaxial strain parameters are researched for the point defects taking the increasing temperatures into consideration. All parameters except the growth temperature of the InGaN layer were kept fixed for all samples. Depending on the growth temperature values, the results indicated a monotonous increasing-decreasing or decreasing-increasing manner. Additionally, the point defects of the blue LED structure on AlGaN layer have been compared to those of InGaN layer. While the lattice relax exchange of both layers were behaving in an opposite manner to each other; hydrostatic and biaxial strain exchanges were behaving in a parallel manner for both layers. As a result, since the points and the defects were carried from one layer to the other, the same tendencies were observed. 

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