摘要:

Pd‐(n‐type) InP Schottky barrier devices have been fabricated on unoxidized and oxidized surfaces and their electrical as well as photovoltaic characteristics have been evaluated. Devices built on the oxidized surfaces show considerably improved characteristics compared with those built on unoxidized surfaces. A saturation current density of 9×10−9A cm−2and barrier height of 0.85 eV have been observed for tunnel Metal‐Oxide‐Semiconductor (MOS) devices compared with 1.1×10−6A cm−2and 0.62 eV for Metal‐Semiconductor (MS) devices. Effective Richardson constants, obtained from activation energy plot of saturation current density, have been found to be 0.66 and 1.9 A cm−2K−2for MOS and MS devices, respectively. Such low values of the Richardson constant, when compared with the theoretical value, provide clear evidence of the modification of current transport mechanism in the presence of an interfacial layer. Photovoltaic cells with an efficiency of 7% have been built on oxidized surfaces without the use of a grid structure or antireflection coatings. Under AMl illumination, the oxidized devices show the following parameters: open circuit voltage = 575 mV, short circuit current = 16.8 mA/cm2, and fill factor = 0.73. Using photoresponse techniques, the diffusion length has been calculated to be 1.78 &mgr;m for MOS devices, a value similar to that obtained for MS devices.

ISSN:0021-8979    

DOI:10.1063/1.329941

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The autoregressive spectral estimation in Fourier transform spectroscopy is examined experimentally in terms of the phase error due to mislocating the zero path difference. Through the nonlinear processing of interferogram, the phase error results in a spectral distortion which somewhat differs from that in the conventional Fourier analysis. A way to reduce the distortion is presented.

ISSN:0021-8979    

DOI:10.1063/1.329943

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Reliability data are presented for (Al,Ga)As double‐heterostructure lasers that emit light near 0.87 &mgr;m. Devices were grown with and without small additions of Sb to the active layer, with some devices grown on high dislocation density substrates. The reliability is more than an order of magnitude better for lasers with GaAs1−ySbyactive layers withy≊0.01 than for lasers with GaAs active layers. The rate of formation of dark line defects is reduced in the Ga(As,Sb) active layer lasers such that not all devices fail due to dark line defects. However, for Ga(As,Sb) active layer lasers grown on high dislocation density substrates, dark line defects formed very rapidly. An increase of roughly an order of magnitude in the substrate dislocation density resulted in a nearly three orders of magnitude decrease in the 70 °C lifetimes of Ga(As,Sb) active layer lasers.

ISSN:0021-8979    

DOI:10.1063/1.329944

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Based upon light intensity measurements, cataphoretic segregation was apparent in dc glow discharges in Ne‐O2mixtures. That this was due to a Penning ionization process which would result in an axial variation in electron energy was apparent from the dependence of the Ne light intensity. The use of gold‐surfaced electrodes greatly reduced—but did not totally eliminate—O2loss processes in the cathode region.

ISSN:0021-8979    

DOI:10.1063/1.329945

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The dielectric constants of two lithium ternary chalcogenides, LiInSe2and LiGaSe2, are obtained to be 8.45 and 8.75, respectively, by capacitance measurements at room temperature. The temperature dependence of dielectric constants of both crystals show linear increase with temperature over the range 77–300 K. The temperature coefficients for LiInSe2and LiGaSe2are 2.90×10−4and 3.80×10−4K−1, respectively. The bond parameters of LiInSe2and LiGaSe2are obtained using the Phillips‐Vechten’s and Levine’s dielectric model. The bond characteristics are discussed within the concepts of ionicity and transverse effective charge.

ISSN:0021-8979    

DOI:10.1063/1.329946

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Finite deformations lead to a stress (&sgr;)‐strain (&egr;) relation of the form &egr; =s′11&sgr;+&dgr;(s′11&sgr;)2, wheres′11is an elastic compliance, and &dgr; is a linear combination of second‐order and third‐order elastic constants. Tensile tests performed on Al whiskers oriented in the ⟨110⟩ direction give &dgr; = 3.8±0.5. This experimental value disagrees with the value of &dgr; = 7.6 computed from third‐order elastic constants measured by Thomas.

ISSN:0021-8979    

DOI:10.1063/1.329984

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Diffusion and disordering experiments have been conducted on an AlAs‐GaAs superlattice with the impurity (Zn) diffusion‐disordering directed along the layers. Diffusion constants (Zn) and ratios at the low temperature of 575 °C have been determined for the as‐grown AlAs (LB∼140 A˚), GaAs (Lz∼140 A˚), and for the resulting impurity‐induced disordered AlxGa1−xAs (x∼0.5). These results confirm the work of earlier experiments, with normal or perpendicular impurity diffusion into an AlAs‐GaAs superlattice, and for Zn diffusion at 575 °C giveD(AlAs)/D(GaAs)∼350.

ISSN:0021-8979    

DOI:10.1063/1.329985

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Electron‐mobility values inn‐type GaAs at 77 K were computed utilizing a variational procedure and taking into account all major scattering mechanisms. Mobility values are tabulated as a function of electron concentrations, providing a convenient means for the determination of the compensation ratio, i.e., the determination of the total concentration of ionized impurities.

ISSN:0021-8979    

DOI:10.1063/1.329986

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The Ga(1−x)AlxAs ternary semiconductor alloys have important applications for optoelectronic devices such as lasers and solar cells; hence electrical properties have been investigated extensively. However, little information is available about the behavior of Zn in metalorganic chemical vapor deposition (MO‐CVD)Ga(1−x)AlxAs. In this paper the electrical properties of Zn‐doped,p‐type Ga(1−x)AlxAs films (0⩽x⩽1.0) grown by MO‐CVD on GaAs:Cr substrates were studied using Hall measurements over a wide range of temperature (77 to 420 °K). The electrical activation energies were determined by measuring the variation of the carrier concentration of Ga(1−x)AlxAs films with temperature. The results indicate that activation energies increase with increasing Al composition (from 23∼26 meV forx= 0 to 140 meV forx= 1.0). The experimental results have been compared with theoretical data calculated from the modified hydrogenic model, and agreement is excellent forx⩽0.5.

ISSN:0021-8979    

DOI:10.1063/1.329987

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Experimental data of carrier mobility and carrier concentration profiles in depth from the surface of silicon wafers implanted with 50 keV P+ions of various doses, isothermally annealed at 480 °C, are reported. Generation and annihilation of mobility controlling defects and carrier trapping centers are discussed with these data. A comment on the carrier recovery of heavily dosed specimens is given.

ISSN:0021-8979    

DOI:10.1063/1.329988

出版商:AIP    

年代:1982

数据来源: AIP