In Situ Monitoring of Electroepitaxial Growth of Thick AlGaAs Layers

In situ growth monitoring technique has been used to analyse growth disturbances during the liquid phase electroepitaxial growth of thick AlGaAs layers. It allowed us to explain the nature of growth instability occurring at the end of the growth and affecting the maximum thickness of AlGaAs layers obtainable by liquid phase electroepitaxy

A Role of Intermediate Charge State in the DX Center Photoionisation in Alx\text{}_{x}Ga1−x\text{}_{1-x}As:Se

Detailed studies of the DX center absorption are presented. They. studies performed on thick AlGaAs:Te layers, give a strong indication for the influence of the intermediate charge state on the DX center photoionisation

Substrate Defects Filtration During Epitaxial Lateral Overgrowth of GaAs

Results on the growth of GaAs on (001) GaAs substrates by the epitaxial lateral overgrowth technique are reported. We show that the ratio of normal to lateral growth rates in the epitaxial lateral overgrowth process can be controlled by the crystallographic orientation of the seeds and by Si adding to the melt. Experimental data showing that the dislocations threading from the substrate are efficiently filtered and cannot propagate to the epitaxial lateral overgrowth layers are presented. These findings prove that the epitaxial lateral overgrowth process is the powerful method to grow epilayers with low dislocation density on high dislocation density substrates

On the High Compositional Uniformity of Thick GaAlAs Layers Grown by Liquid Phase Electroepitaxy

The results of electroepitaxial growth of thick GaAlAs layers on GaAs substrates are presented. It is experimentally proven that effective convective mixing of the solution volume results in the compositional uniformity of GaAlAs layers, even in spite of the high compositional non-uniformity of the material supplying the solutes (Al, As) to the solution during the growth of the layers. For the first time this allowed us to grow uniform GaAlAs layers with thicknesses up to 200-300 μm in a wide composition range from a small (5 g) amount of solution

New DX-Related Photoinduced Absorption in AlGaAs:Te

Absorption measurements on thick AlGaAs:Te layers reveal a new absorption band at ca. 0.55 eV. Also the absorption coefficient of the DX-center ground state was measured directly for the first time

Electron Spin Resonance Studies of Te Doped AlGaAs Epilayers

Results of electron spin resonance studies of tellurium doped AlGaAs epilayers are presented. We demonstrate a new approach to the studies of shallow donor-deep DX level transformation upon illumination or with an increase in temperature. The processes can be monitored by observing the changes of magnitude of an unidentified ESR signal of AlGaAs

New Local Vibrational Modes Related to Silicon in Bulk AlGaAs

A silicon-related local vibrational mode absorption in AlGaAs is reported for the first time. It consists of six peaks grouped around 450 cm$\text{}^{-1}$ which form a distinct pattern. We believe that the new local vibrational mode absorption is a fingerprint of a single defect. Among the discussed microscopic structures the most plausible is a Si$\text{}_{Ga}$-Si$\text{}_{As}$ pair complex with Si$\text{}_{As}$ acceptor interacting with different Ga, Al nearest neighbour local environments

Optical and Electrical Properties of Bulk GaSb and AlGaSb

Optical measurements of bulk GaSb:S reveal the structure of the lattice two phonon absorption and acceptor-valence band transitions. A sulphur related local vibrational modes and several bands related to the optical transitions from the ground state of the acceptor level are observed. A comparison of transport and optical measurements for GaSb:Te and AlGaSb:Te shows that in the alloy it is easier to obtain high concentrations of the electrically active Te impurity