ISSN:0734-211X    

DOI:10.1116/1.584413

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

The evolution of the structural and optical quality of molecular‐beam epitaxial (MBE) grown InAs/In0.52Al0.48As pseudomorphic quantum wells with increasing well thickness has been analyzed by transmission electron microscopy (TEM) and photoluminescence measurements. TEM was used to assess the commensurability of the samples as well as to confirm the build up of stress as the InAs layer is made thicker. Under our growth conditions, intense intrinsic photoluminescence is observed for InAs layers as thick as 30 Å. Beyond this thickness a deterioration of the photoluminescence characteristics occurs due to roughening of the interfaces rather than to relaxation of the InAs lattice.

ISSN:0734-211X    

DOI:10.1116/1.584414

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.584416

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

Lattice mismatched 0.5 to 1‐μm‐thick GaAs1−xSbxepilayers were grown on (100)n‐type GaAs by molecular‐beam epitaxy (MBE) throughout the whole composition range and characterized for Sb content up to 0.76. The Sb incorporation coefficient is found to be 0.42 at a substrate temperature of 480 °C. The epilayer quality was examined by x‐ray diffraction, photoluminescence, and photoresponse. The relationship between energy band gap of GaAs1−xSbxand Sb content at room temperature is found to be in good agreement with the result of Nahoryetal. and that at 77 K is established and can be reasonably described by the estimated one from the binary band gaps of GaAs and GaSb at 77 K and the ternary band gaps of GaAs1−xSbxat 300 K. Both majority electron and hole traps in GaAs1−xSbxepilayers were characterized.

ISSN:0734-211X    

DOI:10.1116/1.584417

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

The effects of growth temperature and As4/Ga beam equivalent pressure ratio on molecular‐beam epitaxial Al0.25Ga0.75As were studied with deep level transient spectroscopy (DLTS), photoluminescence (PL), secondary ion mass spectrometry (SIMS), Hall effect, capacitance profiling, and Nomarski microscropy. The room temperature photoluminescence efficiency is controlled by a deep trap atEc−0.79 eV. Careful analysis shows that the trap concentration is independent of the oxygen concentration. The dependence of this trap on growth temperature and V/III ratio suggests that this trap is related to stoichiometric defects caused by arsenic rich growth. A strong correlation between trap concentration and surface roughness supports the idea that this trap forms as a result of nonstoichiometric growth. SIMS measurements show that the incorporation of oxygen, sulfur, and carbon decreases as the growth temperature increases. Finally, the Hall mobility is found to decrease as the growth temperature increases. This drop in mobility may be caused by material inhomogeneity caused by changes in the growth kinetics.

ISSN:0734-211X    

DOI:10.1116/1.584418

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.584375

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.584377

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

摘要:

The quality of molecular‐beam epitaxy (MBE) growth GaAs–AlGaAs are essential for the properties of new type microstructural devices. Improved growth conditions in MBE have permitted the fabrication of high‐quality ultrathin microstructural materials. In this paper, we report the preparation of MBE grown high‐quality GaAs–AlGaAs quantum wells (QW’s) and their properties. The 1.2 meV FWHM ofE1hindicates the high quality of the material. Growth conditions (especially growth temperatureTsand precise control of the layer thickness) and the substrate preparation are important factors for MBE growth of high‐quality ultrathin microstructural materials. The molecular‐beam sources of our MBE system are vertical type Knudsen cells employing PBN crucibles. Entire component parts of our MBE system were made in China.

ISSN:0734-211X    

DOI:10.1116/1.584378

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.584379

出版商:American Vacuum Society    

年代:1988

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.584380

出版商:American Vacuum Society    

年代:1988

数据来源: AIP