摘要:

Reflectance anisotropy spectroscopy (RAS) has been used to investigate the As/P exchange reaction for group V stabilized InP(001) surfaces exposed toAs2and/orP2, under molecular beam epitaxy conditions. By comparing RAS spectra taken before, during, and afterAs2exposure it is possible to confirm that the As/P exchange reaction is exactly reversible over a range of temperatures from 420 to 560 °C. Time-resolved RAS measurements of the reaction rate, monitored at an energy of 2.65 eV, indicate that the activation energy for the exchange is 1.23±0.05 eV. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118595

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We utilize an inverted heterostructure grown on (311)A GaAs to realize a two-dimensional hole gas (2DHG) with a built-in back gate. The density of the 2DHG is easily and reproducibly varied between5×109and5×1011 cm−2. The mobility of the 2DHG is highly anisotropic in the (311)A plane. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118596

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Recombination dynamics of dense excitonic systems in CdxZn1−xS–ZnS quantum-well structures has been studied by means of time-resolved luminescence spectroscopy. Experimental evidence for biexciton formation was obtained. Furthermore, ultraviolet stimulated emission was observed just at the energy position of the biexciton luminescence. It was proposed that the stimulated emission was due to the biexciton decay process. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118597

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Single-level interface states inn-type GaAs, which were incorporated by planar doping of deep-level defects, are investigated. Discrete electronic traps are directly identified as interface states by admittance-bias spectra. It is experimentally demonstrated that the characteristic response time is determined by both the emission and the capture rate when interface states are investigated by admittance spectroscopy. The transition between capture- and emission-controlled admittance spectra is observed. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118598

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We describe a processing technology for patterning InAs/AlSb heterostructures far in the submicron regime. The processing is based on a new, highly selective wet etchant for AlSb. We discuss the electrical characterization of narrow ballistic channels (down to ≈140 nm width) realized with present technology, and demonstrate that the processing preserves the high mobility of the material. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118599

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

An air-bridged, 120-nm-thick semiconductor slab with a two-dimensional (2D) square array of through holes on a 480 nm pitch (&Lgr;) was fabricated using selective wet etching techniques. The second order photonic resonances of the structure were studied by comparing broadband optical scattering data with numerical solutions of Maxwell’s equations. Features observed in these spectra over a 1200cm−1range, near 9500cm−1,indicate that the 2D texture splits the energy degeneracy of slab modes with propagation constants {±2&pgr;/&Lgr;,0} and {0,±2&pgr;/&Lgr;} by as much as 14&percent;. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118570

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report hole effective mass calculations ofSi1−xCxandSi1−yGeyalloys. All calculations are based on a 16×16 Hamiltonian matrix constructed from the linear combination of atomic orbital approximation with spin-orbit interaction taken into consideration. The 1 meV constant energy surfaces below the valence band edge are used to determine the nominal hole effective masses. The effective masses of light hole and heavy hole ofSi1−yGeyalloys vary as linear functions of Ge content and increase linearly as the hole energy increases from 1 to 15 meV. The heavy hole effective masses ofSi1−xCxalloys, however, exhibit a totally different trend. The effective mass ofSi1−xCxremains relatively unchanged fromx=0.0tox=0.9, and increases abruptly by a factor of two fromx=0.9tox=1.0. The nonparabolicity increases as the C content rises up tox=0.9, and nearly disappears when turning into pure diamond. The interaction between the split-off hole band and the heavy hole band is proposed for the anomalous behavior of the heavy hole effective masses of SiC alloys. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118558

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report on the fabrication and characterization of Mg-doped green light emitting diodes (LEDs) over cubic (111) MgAl2O4substrates with a very strong impurity band electroluminescence. A 0.2-micron-thick Mg-doped In0.13Ga0.87N layer was used in the active region of mesa type LED structures. The emission spectrum was centered at 510 nm (green) with a full-width at half-maximum of 60 nm. At a forward bias current of 20 mA the output power and the external quantum efficiency were about 200&mgr;W and 0.3&percent;. The origin of green light in the Mg-doped In0.13Ga0.87N layer has also been studied by time resolved photoluminescence. Our study demonstrates impurity band LEDs to be a viable alternative to band edge emission green LEDs with high indium mole fractions in the active region. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118557

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

InAsxSb1−x/InP1−x−yAsxSbydouble heterostructures have been grown on InAs substrates by metal-organic chemical vapor deposition. The minority carrier leakage to the cladding layers was studied with photoluminescence measurements on the InAsSb/InPAsSb double heterostructures. A carrier leakage model is used to extract parameters related to the leakage current (diffusion-coefficient and length) from experimental results. Using the obtained parameters, the temperature dependence of the threshold current density of InAsSb/InPAsSb double heterostructure lasers is predicted and compared with experimental results.©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118559

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We have investigated the optical properties of single disks comprising buried quantum wells fabricated byin situelectron-beam lithography by using a low-temperature microphotoluminescence method. Photoluminescence images of a disk array showed the distribution due to emissions from single disks with diameters down to 0.1 &mgr;m. In the photoluminescence and photoluminescence excitation spectra of single disks, the peak positions were almost constant irrespective of disk diameter. Moreover, the photoluminescence spectra had almost equal peak intensities when corrected for the disk diameter and the distribution width in the photoluminescence image. These optical properties indicate successful fabrication of buried quantum-well structures. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119077

出版商:AIP    

年代:1997

数据来源: AIP