Molecular beam epitaxy growth and characterization of CdTe heterostructures on GaAs-effect of interface, growth, and annealing conditions to crystal quality
Arı, Ozan, author.

Molecular beam epitaxy growth and characterization of CdTe heterostructures on GaAs-effect of interface, growth, and annealing conditions to crystal quality

Arı, Ozan, author.

Yazar Ek Girişi
Arı, Ozan, author.

Fiziksel Tanımlama
xx, 179 leaves: illustrarions, charts;+ 1 computer laser optical disc.

Highly crystalline CdTe structures are desired for solar cells, x-ray detectors, electro-optical modulators, and especially in Hg1-xCdxTe infra-red detectors. Epitaxial growth of Hg1-xCdxTe infra-red layers are usually performed on lattice matched bulk CdZnTe substrates. But, limited size and fragile nature of the CdZnTe have led to a push for alternative substrates such as GaAs. The large lattice mismatch between Hg1-xCdxTe and GaAs requires an implantation of a buffer layer such as CdTe. In addition (211)B orientation is preferred due to high sticking coefficient of Hg on this orientation and suppression of twin formation. In the first part of this study, the effect of the thermal deoxidation of GaAs(211)B surface on which CdTe layers grown was investigated by various in situ and ex situ experimental techniques. The changes in the surface chemical structure and morphology of GaAs(211)B substrates with As4 and In assisted deoxidation under various conditions were presented. Secondly, the effect of the growth conditions on CdTe epilayers by using molecular beam epitaxy were investigated in two parts; (1) the initiation of the CdTe growth and (2) the equilibrium growth conditions. The correlations between the structural defects, twins, point defects, and dislocations with the growth conditions are determined. Thirdly, the effect of the cyclic annealing to the crystal and surface quality of the CdTe epilayers were investigated by using different temperatures during the annealing. Finally, the effect of the temperature uniformity during the production of the CdTe layers was investigated by the two substrate heater geometries consisting of rotational symmetric and tilted at the edge. A new approach to study the dislocations with different types of cores proposed by Ayers is applied to the zinc blende (211) crystal orientation. It has been shown that the dislocations having two different cores responded differently to both growth and annealing conditions. The results of the experimental techniques probing the dislocation density in CdTe layers are not well correlated with each other due to dual origin of these dislocations. The compressive and biaxial stresses building in the CdTe layers due to growth and annealing conditions were resolved with the investigation of the optical properties of the layers.

Konu Başlığı
Molecular beam epitaxy.

Yazar Ek Girişi
Öztürk, Orhan,

Tüzel Kişi Ek Girişi
İzmir Institute of Technology. Physics.

Tek Biçim Eser Adı
Thesis (Doctoral)--İzmir Institute of Technology: Physics.
İzmir Institute of Technology: Physics--Thesis (Doctoral).

Elektronik Erişim
Access to Electronic Versiyon.

LibraryMateryal TürüDemirbaş NumarasıYer NumarasıDurumu/İade Tarihi
IYTE LibraryTezT001672QC611.6.M64 A69 2017Tez Koleksiyonu