摘要:

The epitaxial lift‐off technique is applied to II–VI based structures. Epilayers of 255 nm thickness containing quantum wells are lifted off their substrates and redeposited onto polyimide coated GaAs. The technique has also been applied to II–VI samples onto which dielectric films had been deposited. Photoluminescence measurements show that the material quality has not been degraded during the processing. The success of this technique with II–VI’s opens up many possibilities for the integration of these materials with metals and dielectrics in vertical structure devices. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113580

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The transient grating technique was used to study the optical properties of hydrogenated amorphous silicon films. A carrier lifetime &tgr;e=3.3 &mgr;s, a diffusion coefficientD=4.4×10−2cm2/s, and effective third order nonlinear susceptibility &khgr;(3)=(5.1±1.0)×10−7esu were measured for &lgr;pump=532 nm. The electronic and thermal contributions of the grating were estimated by diffracting a continuous wave HeNe laser beam. For intensities 1.4–4.1 mW/cm2, ∼68% of the response at 633 nm is of electronic origin. A slowly rising diffraction component was also observed. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113581

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The flux parameters employed during molecular beam epitaxy of ZnSe on GaAs control both the heterojunction band alignment and the optical quality of the II–VI wide‐gap layer. Independent optimization of the band discontinuities and ZnSe optical properties was achieved by fabricating a 2‐nm‐thick interface layer in nonstoichiometric conditions to control the band alignment, followed by the optically active layer in near‐stoichiometric conditions. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113582

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The behavior of the electron impact‐ionization coefficient &agr;nin In0.53Ga0.47As is measured with unprecedented sensitivity down to very low electric fields. The data are derived from measurements of the multiplication coefficientM−1 in suitably designed heterojunction bipolar transistors. Previously available data are extended by two orders of magnitude in the low field domain, down to &agr;n≊1 cm−1. The experimental behavior of &agr;nat fields below 200 kV/cm is in agreement with the theoretical prediction of a weak field dependence of &agr;nat low electric fields. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113583

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We have measured dark DC conductivity and time‐of‐flight (TOF) of carriers in self‐supporting porous silicon films in the temperature range 298–480 K. The darkI‐Vcurves show superlinear behavior with activation energies of 0.38–0.67 eV. The TOF measurements allowed us to evaluate the drift‐length of non‐equilibrium carriers and revealed a significant decrease of the collected charge with increasing delay (tdel≥1 ms) of the exciting 3 ns laser pulse after the voltage application, probably due to field redistribution in the Si crystallites. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113584

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The optically excited luminescence of epitaxial InAs has been studied at 1.4 K, revealing well‐resolved emission lines identified as the exciton–polariton, neutral–acceptor–bound exciton principal and two‐hole transitions, donor–acceptor pair band, and phonon assisted transitions. These features are seen in samples of high purity InAs grown by metalorganic chemical vapor deposition on InAs substrates using tertiarybutylarsine and trimethylindium. Only one acceptor species is observed, having a 1 S3/2–2 S3/2transition energy of 13.39±0.01 meV, and an acceptor–bound exciton binding energy of 2.11±0.03 meV. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113825

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The room‐temperature photoinduced switching of an InGaAs/AlAs resonant‐tunneling diode is demonstrated. When illuminated at an irradiance of greater than 20 W cm−2using 1.3 &mgr;m radiation, the resonant‐tunneling diode switches from a high‐conductance to a low‐conductance electrical state and exhibits a voltage swing of 600 mV. The switching characteristics are reversible and, in the absence of light, the detector returns to its original high conductance operating state. Small‐signal optical measurements performed with the device biased prior to resonance demonstrate a 3 dB bandwidth of ∼1.5 GHz. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113826

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We have observed the dressed‐exciton oscillating emission in the time domain and the associated spectral splitting in the frequency domain from a GaAs single quantum well microcavity over a very broad range of cavity resonant wavelengths. The spectral splitting and temporal oscillation period have been measured to be nearly constant over two orders of magnitude variation of pump intensity, which confirms the linear bosonic feature of Wannier excitons in the weak excitation regime. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113827

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The effects of an inhomogeneous stress field on the heat transport in semiconductors are qualitatively studied. Stress‐induced spatial variations in lattice constant results in changes in phonon frequency and hence, in the phonon distribution leading to diffusion of phonons which constitutes heat flux at the macroscopic level. It is also found that this leads to a fractional change in thermal conductivity that is linear with the local stress tensor. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113828

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

p‐type conduction in InN‐containing nitrides doped with Mg has been achieved by metalorganic vapor‐phase epitaxy. The hole concentration at room temperature is as high as 7×1017cm−3. The activation energy of a Mg acceptor is estimated to be 204 meV.D–Apair emission with peak wavelength of about 405 nm is enhanced by thermal annealing. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113829

出版商:AIP    

年代:1995

数据来源: AIP