Surface resistance of single-crystal copper in the millimeter-wave region at room temperature

Measurements of the surface resistance of plane surfaces of single-crystal copper were carried out at 35 GHz. They indicate the existence of an anomalous skin effect at room temperature. The surfaces were prepared in stress-free processes, annealed, and manipulated in purified hydrogen and argon.     

Thermionic-field emission through silicon Schottky barriers at room temperature

Current transport via thermionic-field emission through Ni-Si diodes having implanted surface layers has been studied for surface fields between 10⁷ and 10⁸ V m^?1. The well defined potential profile in these structures enables a close comparison to be made between the calculated and measured thermionic-field emission currents and it is shown that the change of reverse current with field can be accurately predicted using the appropriate electron effective mass in the direction of current flow. For typical barrier heights, the field dependence of the electron current through a triangular barrier with image force correction is very nearly exponential with an effective tunnelling distance between 25 and 30 Å at 300K.     

Strong room temperature photoluminescence from erbium-doped siliconmonoxide

Evaporated films of SiO:Er on silicon substrates are shown to exhibit strong photoluminescence after annealing at 600°C for 30 min in argon. With an erbium concentration of ~2.7×10²⁰ cm ^-3, the ⁴I_13/2-⁴I_15/2 transition is found to decay with two exponential components     

制备纳米发光氧化锌的新方法

采用一种全新的高电压电解方法,制得了室温条件下具有可见光致荧光的ZnO颗粒。这一制备技术具有取材容易、设备简单、条件温和、对环境友好、具有绿色合成的特点。探讨了电解制备ZnO的最佳实验条件。用X射线衍射、荧光分光光度计、透射电镜、透光率等实验手段对电解样品进行了表征,并对反应机理进行了初步探讨。结果表明,该方法制得的ZnO颗粒粒度小,结构为纤锌矿型多晶,室温光致荧光效应强。     

Luminescence of porous silicon in the infrared spectral region at room temperature

A method for preparing mesoporous silicon on n-type substrates has been developed. The material exhibits two intense bands of photo-and electroluminescence at room temperature: a primary one in the range 1.4–1.8 eV, and a low-energy infrared band near 1–1.2 eV. It is shown that the position of the primary emission maximum and the intensity of the band can be controlled. The properties of the primary band are explained in terms of a quantumsize model for formation of porous silicon, while the low-energy band is explained as radiative recombination in larger non-quantum-size crystallites. Fiz. Tekh. Poluprovodn. 31, 365–369 (March 1997)     

Micromachined bolometer with single-crystal silicon diode as temperature sensor

An infrared-sensitive micromachined bolometer integrated with a single-crystal silicon diode as temperature sensor was designed and fabricated. An island of single-crystal silicon containing the diode underneath the bolometer membrane was centered and thermally isolated from the substrate. Diode temperature sensitivity biased by constant current was found to be -2.6 mVK/sup -1/ and bolometer thermal conductivity of 2.0/spl times/10/sup -7/ WK/sup -1/. Due to its negligible self-heating effect, the bolometer could be biased permanently and its output signal integrated for an unlimited time. The utilization of diode-based bolometer as focal plane array basic block is discussed.     

Avalanche light-emitting diodes operating at room temperature based on single-crystal Si:Ho:O

Electroluminescence of Ho³⁺ ions has been observed for the first time in diode structures based on single-crystal silicon doped with holmium and oxygen. The product of the effective cross-section for excitation of Ho³⁺ ions and the lifetime of the first excited state was determined under avalanche breakdown conditions. Fiz. Tekh. Poluprovodn. 33, 931–932 (August 1999)     

Interface state analysis using integrated room temperature gated photoluminescence

A gated room temperature integrated photoluminescence (PL) technique for estimating interface state densities in III-V metal-insultaor-semiconductor (MIS) structures is described. The use of gated low temperature spectral PL has already been demonstrated to be more sensitive than conventional 1 MHz capacitance-voltage (C-V) measurements. Room temperature integrated PL was measured on InP MIS structures and interface state densities of approximately 10/sup 12/ (cm/sup 2/ eV)/sup -1/ were calculated, similar to those reported earlier. Furthermore, the elimination of spectroscopic and cryogenic equipment makes this technique simpler and more cost effective than the spectral method, more comparable to C-V measurements.<>     

室温下单晶硅压痕微裂纹的形成与扩展

用透射电镜定位观察研究了在室温下高纯单晶硅显微压痕表面radial脆性微裂纹的纳观形变 ,阐述了塑性变形对微裂纹形核、扩展及开裂的影响。发现 :室温下单晶硅的压痕前沿经历了极复杂的非线性演化 :前沿区的位错发射与运动 (Kcleave>Kemit时 )、解理微纹形核与扩展 (σ塞 >σth 时 )。观察到压痕前沿发生塑性诱导解理和解理胚不连续形核与扩展的过程     

Characterization of silicon oxide films grown at room temperature by point-to-plane corona discharge

Oxide films grown on silicon in dry oxygen ambient at room temperature by negative point-to-plane corona discharge are investigated. A significant oxidation rate is observed at room temperature using this technique. Electrical properties of these room termperature grown oxides are examined. The capacitance-voltage measurements on the MOS structures fabricated from these oxides indicate a negative flat-band voltage of −1.5 V. Interface state density distribution in the range of 10¹⁰−10¹³ cm⁻²(eV)⁻¹ is observed with a value of 2×10¹⁰ cm⁻²(eV)⁻¹ at 0.17 eV above the valence band edge. Electrical conduction through the oxide is greater for negative values of applied gate bias voltages and the magnitude of conduction through the oxide decreases with decreasing current density during the corona discharge. Oxides grown at room temperature by this technique may find selective application in low temperature device processing.     

Nature of a temperature hysteresis of effective shear modulus in single-crystal silicon

The behavior of the effective shear modulus G _ef and internal friction in Si is comprehensively studied in the temperature range in which an anomalous hysteresis G _ef (T) exists. It is shown that this hysteresis is caused by mobile dislocations and that the pinning of these dislocations by radiation defects results in total blocking of the hysteresis. Metastable dynamics of the transformations responsible for the anomalous behavior of G _ef (T) are detected.     

Edge photoluminescence of single-crystal silicon with a <Emphasis Type=Italic>p-n</Emphasis> junction: Structures produced by high-efficiency solar cell technology

The systematic features and kinetics of edge photoluminescence of silicon structures produced by the high-efficiency solar cell technology is studied at different voltages applied to the p-n junction. It is shown that the effect of modulation of the edge photoluminescence intensity by a dc voltage applied to the p-n junction is qualitatively similar to the effect induced by excitation of photoluminescence by laser radiation at the wavelengths 658 and 980 nm. The possibility of modulating the edge photoluminescence power by varying the resistance parallel to the p-n junction is demonstrated. It is found that, at zero voltage, the rise time constant of the photoluminescence intensity far exceeds the decay time constant. However, as the dc forward current is increased, the decay time constant approaches the rise time constant. To interpret the results, the concepts of the second, more efficient saturable recombination channel coexisting with the common Shockley-Read-Hall recombination channel in the structure are developed. The study extends the functional capabilities of the luminescence technique in determining the effective lifetimes of charge carriers.     

Amorphous lead titanate: a new wide‐band gap semiconductor with photoluminescence at room temperature

This paper describes a new amorphous wide‐band gap semiconductor with photoluminescence (PL) at room temperature. The amorphous PbTiO₃ was prepared by a sol–gel‐like process in powder and thin film form. The optical property and the PL behaviour showed a direct relation to the amorphous structure. The PL peak energy can be controlled by the change of the exciting surge energy. Copyright © 2000 John Wiley & Sons, Ltd.     

MOSFET's negative transconductance at room temperature

Negative transconductance is reported for the first time at T=300 K for NMOS transistors fabricated with different technologies and oxide thickness in the 3-20 nm range. The effects of drain bias, channel length, oxide thickness as well as substrate doping and bias on the phenomenon are investigated. The results are interpreted in terms of surface-roughness limited mobility, and parameters for mobility modeling at high effective fields are extracted     

Interaction of fullerene with single-crystal silicon

The optical properties of layers of C₆₀ fullerene on a silicon substrate are studied before and after a reducing annealing at 900–1050°;C in a hydrogen atmosphere in order to detect the formation of silicon-carbide clusters. It is shown, on the basis of Raman scattering, infrared absorption, time-resolved photoluminescence spectra, and ellipsometric measurements, that the SiC clusters are not detected at the accuracy of the methods used. After annealing, the layer is in the form of a porous hydrogen-rich film of disordered graphite, possibly with a small amount of fullerene molecules.     

Oxidation and stress relief in air at room temperature of amorphous silicon hydrogenated in a glow discharge

Glow-discharge-hydrogenated amorphous silicon (a-Si : H) was found to be oxidized in the following two ways after exposing to air at room temperature; first, thin oxide films grew uniformly on the a-Si : H, slowly with increase of exposure time; secondly, oxide with a columnar morphology grew rapidly with the increase of exposure time and the cross section of the columnar oxide was small. Mechanical stress caused by the differences of the thermal expansion coefficient and the crystallographical structure between the a-Si : H and substrates was relieved with the increase in the amount of the columnar oxide.     

Low-temperature photoluminescence in holmium-doped silicon

In this paper the photoluminescence (PL) of holmium-doped silicon is discussed. The silicon was first implanted with holmium ions at energies of 1–2 MeV and doses of 1×10¹³–3×10¹⁴ cm⁻², and then annealed at temperatures of 620–900 °C for 0.5–1 h. In order to increase the concentration of electrically and optically active centers, the silicon was implanted a second time with oxygen ions at energies of 0.14–0.29 MeV and doses of 1×10¹⁴–3×10¹⁵ cm⁻². Several photoluminescence lines, which are attributable to the transitions of electrons from the first excited state of the Ho³⁺ ion (⁵ I ₇) to the ground state (⁵ I ₈), were observed. The amplitudes of the most intense lines, which correspond to transitions at frequencies 5119 and 5103 cm⁻¹, decreased by more than an order of magnitude in the temperature range 4.2−78 K. The PL intensity of the holmium ions increased with increasing concentrations of the implanted rare-earth ions and oxygen. Fiz. Tekh. Poluprovodn. 33, 420–422 (April 1999)     

Manufacturing regression models of silicon single-crystal photoconverters

An experimental regression model has been proposed that specifies the relationship of the efficiency factor of silicon single-crystal photoconverters as a function of the diode (imperfection factor A, series resistance R _s, saturation current I ₀) and manufacturing (substrate thickness h, thickness of the doping layer of liquid-solution composition h _LSC) parameters under conditions of a small lot of (6–12) samples on the basis of the first-order regression equation. The model verification was performed by the F-criterion of Fisher. The search for optimal diode and manufacturing parameters was performed by the efficiency maximum criterion using regression equations.