摘要:

For a bulk GaAs semiconductor laser amplifier the evolution of the optical gain after a 200 fs pulse excitation is calculated by including carrier–carrier and LO‐phonon–carrier scattering in terms of the Boltzmann collision integrals. For an injected light pulse in the gain (absorption) region the optical gain shows a transient decrease (increase) followed by relaxation towards a lower (higher) level. Around the transparency point the broadening of the optical transition due to the decay of the induced interband polarization yields a transient decrease of the optical gain although the carrier density does not change. This behavior agrees qualitatively well with measurements of M. P. Kesler and E. P. Ippen [Appl. Phys. Lett.51, 1765 (1987)]. The temperature relaxation after the excitation is examined. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.114252

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A novel method for the preparation of bonded and etch‐back silicon‐on‐insulator is presented and demonstrated in which the surface of the to be thinned silicon wafer near the oxide is biased to inversion, so the bulk of this silicon wafer can be removed by anodic etching using the depletion layer as an etch stop. The high etching selectivity between the bulk silicon wafer and the depletion layer makes it possible to produce a micron/submicron‐thick active silicon layer with good thickness uniformity across a 3 in. silicon‐on‐insulator wafer. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114253

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

An all‐organic light amplification device was designed using organic electroluminescent diode coupled with photoresponsive organic perylene pigment film as an electron photoinjecting layer. Amplification gain of photon conversion from red to red reached 25‐folds with the assistance of the large photocurrent multiplication in a perylene film. Moreover, optical switching behavior caused by the feedback of output light to the photoresponsive layer was observed. Since the spatial pattern of light was conserved, the present device has the potential to grow into new optoelectronic devices for optical image processing. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114254

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The local lattice distortion relating to the phosphorus antisite defect (PGa) in the P+‐ion‐implanted GaP layer was studied using Rutherford backscattering (RBS), photoacoustic (PA), Raman scattering, and photoluminescence (PL) methods. The displacement fraction due to the excess phosphorus in 800 °C annealed samples is estimated to be ∼2×1020/cm3by RBS channeling measurements. The slight reduction of the LO‐TO phonon frequency splitting of the annealed P+‐ion‐implanted GaP with respect to the unimplanted one indicates the presence of PGa, corresponding tox=0.0084 of Ga1−xP1+x. This is consistent with the displacement fraction estimated by RBS. A PL emission relating to PGais observed at 716 mm (1.73 eV). ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.114255

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We present photoinduced intersubband absorption measurements in HgCdTe undoped quantum wells. The transition energies and the linewidths are well described by a full 8×8k⋅pKane model calculation. Also, based on this model we show that different in‐plane effective masses for the first and second electron subbands should be considered in order to properly fit the low energy side of the experimental spectra. The experimental results can be explained using the calculated intersubband oscillator strength with no exciton enhancement. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114256

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A laser direct‐write process has been applied to structure silicon on a nanometer scale. In this process, a silicon substrate, placed in a chlorine ambience, is locally heated above its melting point by a continuous‐wave laser and translated by high‐resolution direct‐current motor stages. Only the molten silicon reacts spontaneously with the molecular chlorine, resulting in trenches with the width of the laser‐generated melt. Trenches have been etched with a width of less than 70 nm. To explain the functional dependence of the melt size on absorbed power, the calculations based on a two‐phase steady state heat model are presented, taking the temperature‐dependent thermal conductivities and optical parameters into account. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114257

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

This letter investigates the gain medium properties in II–VI blue‐green quantum well semiconductor lasers, including band structure and carrier interactions in the electron‐hole plasma are found to be significantly more important than in infrared III–V lasers. In particular, the interband Coulombic enhancement of the optical transitions, together with a band gap renormalization result in an increase in gain and a reduction in the antiguiding or linewidth enhancement factor. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114258

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Inverse staggered polycrystalline silicon (poly‐Si) and hydrogenated amorphous silicon (a‐Si:H) double structure thin film transistors (TFTs) are fabricated based on the conventionala‐Si:H TFT process for the application to liquid crystal display panels with peripheral driver circuits integration. After depositing a thin (20 nm)a‐Si:H using the plasma chemical vapor deposition technique at 300 °C, Ar+and XeCl (300 mJ/cm2) lasers are irradiated on the peripheral driver circuits areas, and then thicka‐Si:H (200 nm) andn+Si layers are deposited again. Field effect mobilities of 10 and 0.5 cm2/V s are obtained for the laser annealed poly‐Si and thea‐Si:H (without annealing) TFTs, respectively. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114259

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A novel method for the formation of ap+‐layer underneath a Si(111)7×7 surface is presented. It is based on annealing of an epitaxial Al/n‐Si(111) interface up to complete desorption of the Al film. This leads to a strong potential variation within the substrate, as observed in Si‐2pcore‐level photoemission spectra with variable sampling depth, while scanning‐tunneling microscopy reveals an unchanged 7×7 reconstructed surface. These observations are consistent with ap+doping of (4±2)×1018/cm3and a lowering of the surface Fermi level by (0.06±0.02) eV. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.114260

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

This letter studies the hydrogen plasma effects on the resistivity, effective free carrier concentration, and mobility of As+‐ and BF+2‐doped polycrystalline silicon (polysilicon) thin films of various thicknesses. It is found that the resistivity increases while the effective free carrier concentration decreases after the plasma treatment as the thickness of the polysilicon film decreases. The mobility typically tends to decrease for the thicker (≳60 nm) polysilicon film, but to increase for the thinner (<60 nm) polysilicon film. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.114261

出版商:AIP    

年代:1995

数据来源: AIP