APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

23 Nov 1992

Volume 61, Issue 21, pp. 2497-2618

Page 1 of 2 Pages Next Page | Jump to Page

Time resolved photoluminescence studies in a reverse biased quantum well laser structure

D. P. Halliday, D. Moss, S. Charbonneau, G. Aers, F. Chatenoud, and D. Landheer

Appl. Phys. Lett. 61, 2497 (1992); http://dx.doi.org/10.1063/1.108160 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
We report measurements of photoluminescence decay time in a reverse biased GaAs/AlGaAs graded index separate confined heterostructure single quantum well (GRINSCH‐SQW) laser, as a function of bias voltage at temperatures of 20, 70, and 150 K. For certain bias voltages and temperatures, we observe extremely fast escape times of optically generated carriers. We propose a simple model based on photogenerated electron recombination in the quantum well, and escape via direct tunneling out of the lower bound electronic level, thermally assisted tunneling out of the upper weakly bound state, or thermionic emission over the barrier. We have performed a theoretical calculation of each of these processes and show that the data agrees well with the direct and thermally assisted tunneling times and that the thermionic emission term underestimates the times.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
78.47.-p Spectroscopy of solid state dynamics
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.40.Gk Tunneling

High frequency attenuated total internal reflection light modulator

O. Solgaard, F. Ho, J. I. Thackara, and D. M. Bloom

Appl. Phys. Lett. 61, 2500 (1992); http://dx.doi.org/10.1063/1.108161 (3 pages) | Cited 26 times

Full Text: | Download PDF

Show Abstract
The modulation efficiency and bandwidth limitations of a new type of light modulator, the attenuated total internal reflection modulator (ATRM), are described. The ATRM is based on coupling a light beam to a surface plasmon wave, and its fabrication is compatible with GaAs integrated circuit technology. We demonstrate modulation to 22 GHz (the extrapolated 1.5 dB optical modulation bandwidth is 26 GHz) and show that devices with high modulation index can be built using existing materials.
Show PACS
42.79.Hp Optical processors, correlators, and modulators
78.66.Qn Polymers; organic compounds
73.25.+i Surface conductivity and carrier phenomena

Bright blue electroluminescence from hole transporting polycarbonate

Chishio Hosokawa, Nobuo Kawasaki, Shuji Sakamoto, and Tadashi Kusumoto

Appl. Phys. Lett. 61, 2503 (1992); http://dx.doi.org/10.1063/1.108162 (3 pages) | Cited 62 times

Full Text: | Download PDF

Show Abstract
Bright blue electroluminescence (EL) was observed for the EL cell with a nonconjugated polymer as an emitting layer. The emitting layer was composed of a hole transporting polycarbonate containing styrylamine as a functional repeating unit (SA‐PC). SA‐PC was soluble in many solvents. It was very easy to form a smooth and dense thin film at a thickness less than 100 nm without any recrystallization. For the EL cell with ITO/SA‐PC/an oxadiazole derivative/Mg:Ag structure, we achieved bright luminance of 130 cd/m2 at a current of 80 mA/cm2 with an applied voltage of 11 V.
Show PACS
85.60.Jb Light-emitting devices
85.60.Pg Display systems
78.60.Fi Electroluminescence
78.66.Qn Polymers; organic compounds

1.3 μm InAsyP1−y/InP strained‐layer quantum well laser diodes grown by metalorganic chemical vapor deposition

Y. Imajo, A. Kasukawa, T. Namegaya, and T. Kikuta

Appl. Phys. Lett. 61, 2506 (1992); http://dx.doi.org/10.1063/1.108163 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
We report on the metalorganic chemical vapor deposition (MOCVD) growth of InAsyPl1−y/InP strained layer quantum wells and the successful lasing of novel InAsyP1−y/InP strained layer quantum well laser diodes at 1.3 μm for the first time. Full width at half maximum of room temperature photoluminescence was as narrow as 30.1 meV with a peak wavelength of 1.29 μm. A very low threshold current density of 0.45 kA/cm2 was obtained on broad contact lasers with a cavity length of 900 μm.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Coulomb enhancement of the third‐order optical nonlinearities in quantum wells

M. Załużny

Appl. Phys. Lett. 61, 2509 (1992); http://dx.doi.org/10.1063/1.108164 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
The investigation of Khurgin and Li [Appl. Phys. A 53, 527 (1991)] on the electrostatic Coulomb enhancement of the third‐order intersubband nonlinearities in stepped quantum wells is extended by taking into account the modification of the intersubband resonant energy by the depolarization effect. It was found that the ratio of the depolarization enhancement factor (ηd) to the electrostatic Coulomb enhancement factor (ηe) strongly depends on the shape of the quantum well. Obtained results show that, in the case of the conventional square quantum well, factor ηd is several times larger than ηe while in strongly asymmetric stepped quantum wells ηd≪ηe.
Show PACS
78.30.Fs III-V and II-VI semiconductors
78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors
42.65.-k Nonlinear optics

Carrier heating and spectral hole burning in strained‐layer quantum‐well laser amplifiers at 1.5 μm

K. L. Hall, G. Lenz, E. P. Ippen, U. Koren, and G. Raybon

Appl. Phys. Lett. 61, 2512 (1992); http://dx.doi.org/10.1063/1.108486 (3 pages) | Cited 49 times

Full Text: | Download PDF

Show Abstract
We present the first polarization studies of femtosecond gain dynamics in strained‐layer multiple‐quantum‐well laser amplifiers. We observe a response consistent with spectral hole burning when the diode is biased in the absorbing regime. In the gain regime, we show that the carriers are heated by free‐carrier absorption and that there is a measurable delay (∼200 fs) in the thermalization of the hot‐carrier distribution. Subsequent cooling to the lattice temperature follows with a time constant of ∼1 ps.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
78.47.-p Spectroscopy of solid state dynamics
78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

A high‐power electron beam source based on the superemissive cathode

T.‐Y. Hsu and M. A. Gundersen

Appl. Phys. Lett. 61, 2515 (1992); http://dx.doi.org/10.1063/1.108165 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
A robust, high current electron beam, produced by emission from a refractory metal cathode operating in the superemissive mode, is reported. Electron beam current of ≳150 A is produced by a back‐lighted thyratron during the conductive phase. Electron energies are several hundred eV and the electron beam has the duration of the discharge pulse. A simple differential pumping scheme has been used to demonstrate extraction of the electron beam into a low pressure (<7 mTorr) region.
Show PACS
41.75.Fr Electron and positron beams
52.80.Hc Glow; corona
52.80.-s Electric discharges

Surface composition of Si‐TaSi2 eutectic cathodes and its effect on vacuum field emission

James J. Hickman, George Bergeron, Mark Czarnaski, and Douglas A. Kirkpatrick

Appl. Phys. Lett. 61, 2518 (1992); http://dx.doi.org/10.1063/1.108166 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
Our research shows that the presence of an oxide layer on the surface of a field emission cathode is deleterious to its performance and that, for successful operation, removal of this layer is necessary before overcoating with another material. We further show that once the surface oxide is removed, cathodes can be protected with a Au overcoat and run in harsh environments. We have demonstrated stable emission for a Au‐coated Si‐TaSi2 cathode for over 100 h in an O2 atmosphere at 5×10−6 Torr.
Show PACS
79.70.+q Field emission, ionization, evaporation, and desorption

Fractal analysis of leakage‐current fluctuations of Si metal‐oxide‐semiconductor capacitors for the characterization of dry‐etching damage

Takaya Miyano, Manabu Fujito, Kiwamu Fujimoto, and Akira Sanjoh

Appl. Phys. Lett. 61, 2521 (1992); http://dx.doi.org/10.1063/1.108168 (3 pages)

Full Text: | Download PDF

Show Abstract
Three categories of leakage‐current fluctuations through the oxide layers of Si metal‐oxide‐semiconductor capacitors are observed in the 5 kHz frequency range. They are classified by the fabrication processes for the polycrystalline silicon gate electrodes of the capacitors: (1) wet etching, (2) dry etching using plasma generated by electron cyclotron resonance, and (3) reactive ion etching. Fractal dimensions of each category of the current fluctuations are evaluated to be: (1) 2.00 (standard deviation σ=0.01); (2) 1.87 (σ=0.10; and (3) 1.71 (σ=0.08), respectively. The results are analyzed in terms of Brownian motion. The decrease in the fractal dimension is ascribed to change in defect structure of the electron traps induced by each dry‐etching process.
Show PACS
85.40.Hp Lithography, masks and pattern transfer
85.30.Tv Field effect devices
81.65.-b Surface treatments
73.50.Td Noise processes and phenomena

Thermally stable ZnO films deposited on GaAs substrates with a SiO2 thin buffer layer

Hong Koo Kim and Michelle Mathur

Appl. Phys. Lett. 61, 2524 (1992); http://dx.doi.org/10.1063/1.108169 (3 pages) | Cited 14 times

Full Text: | Download PDF

Show Abstract
SiO2 thin films (1000‐Å thick) were sputter deposited on GaAs substrates as a buffer layer in order to alleviate a thermal mismatching problem between ZnO films and GaAs substrates. Thermal stability of sputter‐deposited ZnO films (0.5–2.0 μm thick) was tested on such a buffered GaAs substrate with a postdeposition heat treatment at 430 °C for 10 min, which is similar to a standard ohmic contact alloying condition. The films sustained the heat treatment well, not showing any crumbling, which has usually been a problem when a ZnO film is deposited directly on a GaAs substrate. The postdeposition anneal treatment also dramatically enhances c‐axis orientation of the ZnO films and relieves intrinsic stress almost completely. These improvements are attributed to a reduction of grain boundaries and voids with the anneal treatment as supported by the scanning electron microscopy and x‐ray diffraction measurement results.
Show PACS
81.15.Cd Deposition by sputtering
77.55.-g Dielectric thin films
68.60.Dv Thermal stability; thermal effects
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

Preparation of Fe nanocrystalline in SiO2 by ion implantation

G. L. Zhang, W. H. Liu, F. Xu, and W. X. Hu

Appl. Phys. Lett. 61, 2527 (1992); http://dx.doi.org/10.1063/1.108170 (3 pages) | Cited 23 times

Full Text: | Download PDF

Show Abstract
We present a novel method, by using an ion implantation and subsequent heat treatment, to prepare Fe nanocrystalline in SiO2. The formation process of Fe granules was monitored by means of conversion electron Mössbauer spectroscopy and the size of which was determined by transmission electron microscopy. The magnetic coercivity of 100 and 70 Oe have been observed at room temperature and 80 K, respectively. A decrease of the coercivity at 80 K is probably caused by the appearance of a multidomain structure in the granules due to reducing the critical radius of single domain.
Show PACS
75.50.Tt Fine-particle systems; nanocrystalline materials
61.72.up Other materials
64.75.-g Phase equilibria
81.30.Mh Solid-phase precipitation

Optically induced absorption and paramagnetism in lead lanthanum zirconate titanate ceramics

W. L. Warren, C. H. Seager, D. Dimos, and E. J. Friebele

Appl. Phys. Lett. 61, 2530 (1992); http://dx.doi.org/10.1063/1.108171 (3 pages) | Cited 18 times

Full Text: | Download PDF

Show Abstract
Electron paramagnetic resonance (EPR) and photothermal deflection spectroscopy measurements have been performed to identify the nature of the centers responsible for the subgap absorption in both unilluminated and ultraviolet (UV) illuminated lead lanthanum zirconate titanate (PLZT) ceramics. In the PLZT ceramics we find that the absorption near 2.6 eV is correlated with the presence of Ti+3 centers. UV exposure of these ceramics leads to the generation of two charged paramagnetic defects, Pb+3 and Ti+3, as well as an increased subgap absorption. These observations demonstrate strong correlations between the UV‐induced EPR and optical responses, suggesting that both are due to the same trapping centers.
Show PACS
77.80.-e Ferroelectricity and antiferroelectricity
71.55.Ht Other nonmetals
76.30.Mi Color centers and other defects
78.30.Hv Other nonmetallic inorganics
78.40.Ha Other nonmetallic inorganics

Cross‐sectional structures of CoNiCr/Cr bilayer and multilayer thin films

B. Y. Wong and E. E. Laughlin

Appl. Phys. Lett. 61, 2533 (1992); http://dx.doi.org/10.1063/1.108143 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
The cross‐sectional structure of CoNiCr/Cr bilayer and multilayer thin films is investigated by HRTEM. Results showed that the orientation relationship between CoNiCr and Cr and the crystallographic orientation of CoNiCr is controlled by the orientation of the Cr column. Similar results are found for the multilayer film. The crystallographic orientation of the Cr interlayer and the second CoNiCr layer is identical to that of the Cr underlayer and the first CoNiCr layer. The misfit at the interface is partially relieved by misfit dislocations and the rest remains as elastic strain.
Show PACS
75.70.-i Magnetic properties of thin films, surfaces, and interfaces
75.50.Cc Other ferromagnetic metals and alloys
81.10.Aj Theory and models of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

Quantitative element analysis in high resolution electron microscopy in both phases of nanocrystalline Fe75.5Cu1Nb3Si12.5B8

Frank van Bouwelen, Jilt Sietsma, C. D. de Haan, and A. van den Beukel

Appl. Phys. Lett. 61, 2536 (1992); http://dx.doi.org/10.1063/1.108485 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
Element analysis is performed in both the crystalline and the amorphous phase of partially crystallized Fe75.5Cu1Nb3Si12.5B8, having a nanocrystalline structure. The crystallites are shown to contain significantly less Nb than the amorphous phase, which is important for understanding the nanocrystallization process. The amount of Si in the crystalline phase is found to be about 13%.
Show PACS
81.30.Hd Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder
81.30.Bx Phase diagrams of metals, alloys, and oxides
75.50.Tt Fine-particle systems; nanocrystalline materials
81.30.-t Phase diagrams and microstructures developed by solidification and solid-solid phase transformations

Low pressure metalorganic chemical vapor deposition of AIN over sapphire substrates

M. Asif Khan, J. N. Kuznia, R. A. Skogman, D. T. Olson, M. Mac Millan, and W. J. Choyke

Appl. Phys. Lett. 61, 2539 (1992); http://dx.doi.org/10.1063/1.108144 (3 pages) | Cited 43 times

Full Text: | Download PDF

Show Abstract
In this letter we report the deposition of high quality single‐crystal films of AIN over basal plane sapphire substrates. A conventional low pressure metalorganic chemical vapor deposition (LPMOCVD) system was used for all the growths reported here. We present the results of conventional and switched atomic layer epitaxial (SALE) depositions. Conventional LPMOCVD yielded single‐crystal AIN films at temperatures in excess of 750 °C. The ALE process in contrast produced extremely smooth single‐crystal AIN layers at temperatures as low as 450 °C. To the best of our knowledge this is the lowest ever reported for chemical vapor deposition of single‐crystal AIN. X‐ray and optical characterization data are presented to compare the quality of the material resulting from the two deposition techniques.
Show PACS
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Barrier parameter variation in Al‐Al2O3‐metal tunnel junctions

Q. Q. Shu and W. G. Ma

Appl. Phys. Lett. 61, 2542 (1992); http://dx.doi.org/10.1063/1.108145 (3 pages) | Cited 15 times

Full Text: | Download PDF

Show Abstract
A trapezoidal potential barrier was used to model an Al2O3 barrier layer in three different tunnel junctions: Al‐Al2O3‐Au, ‐Ag and ‐Cu. The trapezoidal tunneling barrier parameters were determined by fitting the calculated I‐V curves to the experimental curves at 77 K. It is found that the barrier width of the Au‐, Ag‐, and Cu‐junction is 24, 25, and 12 Å, respectively, and that the barrier heights of the three different junctions are close to each other at the Al‐Al2O3 interface, but they are 1.05, 0.85, and 3.10 eV at the Al2O3‐Au, ‐Ag, and ‐Cu interface, respectively. The Auger depth profiles of the junctions suggest that the variation of the barrier parameters with the top electrode may be due to diffusion of the top electrode atoms into the barrier and the occurrence of the oxidation reaction between the Al2O3 and the top metal electrode atoms in the region of the interfaces.
Show PACS
73.40.Rw Metal-insulator-metal structures
73.40.Gk Tunneling
85.30.Mn Junction breakdown and tunneling devices (including resonance tunneling devices)
68.35.Fx Diffusion; interface formation

Structure and thermal stability of Cu‐In precipitates and their role in the semi‐insulating behavior of InP:Cu

R. P. Leon, P. Werner, C. Eder, and E. R. Weber

Appl. Phys. Lett. 61, 2545 (1992); http://dx.doi.org/10.1063/1.108121 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
InP was found to be semi‐insulating after Cu diffusion. This conversion of both n‐InP and p‐InP was ascribed to the presence of Cu‐In precipitates that act as buried Schottky barriers. The thermal stability of both the precipitates and the electrical properties of InP:Cu were studied after high temperature annealing treatments. Atomic resolution microscopy was used to determine the structure of these precipitates. Diffraction studies of some of these inclusions show that they have the structure of the metallic hexagonal compound Cu16In9. The concentration of Cu‐In precipitates was found to be comparable with what our calculations show would achieve intrinsic behavior due to the effect of the metallic inclusions.
Show PACS
72.80.Ey III-V and II-VI semiconductors
61.72.Bb Theories and models of crystal defects
61.72.U- Doping and impurity implantation

In situ observation of growth rate enhancement during gas source molecular beam epitaxy of Si1−xGex alloys on Si(100) surfaces

S. M. Mokler, N. Ohtani, M. H. Xie, J. Zhang, and B. A. Joyce

Appl. Phys. Lett. 61, 2548 (1992); http://dx.doi.org/10.1063/1.108122 (3 pages) | Cited 14 times

Full Text: | Download PDF

Show Abstract
Using reflection‐high‐energy‐electron‐diffraction intensity oscillations the growth rate of Si1−xGex alloys at various compositions and different growth temperatures has been studied in situ. It was found that the growth rate shows a strong dependence on GeH4 flux at low temperatures (T<600 °C), while at high temperatures (T≳600 °C) the growth rate is nearly independent of the GeH4 flux but proportional to the incident Si2H6 beam flux. In addition to the enhanced growth rate, a lower activation energy is observed in the low temperature region when compared to Si homoepitaxy from Si2H6. This suggests that surface germanium atoms act as good sites for hydrogen removal which is known to inhibit Si growth from hydride sources at low temperatures. Above 600 °C, however, surface hydrogen is desorbed thermally and the addition of GeH4 has little effect on the growth rate.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Evaluation of surface roughness of technological InP substrates by in situ scanning tunneling microscopy imaging in H2SO4 solution

Y. Robach, M. Phaner, C. de Villeneuve, and L. Porte

Appl. Phys. Lett. 61, 2551 (1992); http://dx.doi.org/10.1063/1.108123 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
The topography of different technological InP substrates has been studied by scanning tunneling microscopy in 0.25M H2SO4, under potentiostatic control. For the best surface preparation corresponding to an ‘‘epiready’’ InP surface, a rms roughness of ∼15–20 Å was measured, approximately ten times higher as for Si surfaces. Finally, it was shown that the growth of a chemical native oxide in HNO3 and its subsequent removal in a dilute HF solution led to a significant improvement of the InP surface topography.
Show PACS
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.65.-b Surface treatments

Improved ohmic contacts for p‐type ZnSe and related p‐on‐n diode structures

Y. Lansari, J. Ren, B. Sneed, K. A. Bowers, J. W. Cook, and J. F. Schetzina

Appl. Phys. Lett. 61, 2554 (1992); http://dx.doi.org/10.1063/1.108124 (3 pages) | Cited 49 times

Full Text: | Download PDF

Show Abstract
The problem of obtaining ohmic contacts for p‐type ZnSe is related to the deep valence band of ZnSe. We have addressed this problem by employing an epitaxial layer of the semimetal HgSe to decrease the interfacial energy barrier, or valence band offset, to about 0.6 eV. This has resulted in improved ohmic contacts for p‐type ZnSe films and related diode structures.
Show PACS
73.30.+y Surface double layers, Schottky barriers, and work functions
73.40.Cg Contact resistance, contact potential
73.40.Ns Metal-nonmetal contacts

Selective growth of Si crystals from the agglomerated Si seeds over amorphous substrates

K. Yamagata and T. Yonehara

Appl. Phys. Lett. 61, 2557 (1992); http://dx.doi.org/10.1063/1.108125 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
Selective growth of Si crystals over amorphous substrates, seeded by the agglomerated single domained Si crystals is demonstrated. Si crystal seeds are formed from the minutely patterned polycrystalline Si films over amorphous SiO2 by the solid‐state agglomeration phenomenon. Periodically placed seeds are grown selectively up to 100 μm by CVD selective epitaxial growth technique. An n‐channel metal oxide semiconductor (NMOS) transistor is fabricated inside a planarized Si island on a fused quartz substrate and operated with an electron mobility of up to 600 cm2/V s.
Show PACS
81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Observation of enhanced hydrogen diffusion in solar cell silicon

Bhushan L. Sopori, Kim Jones, and Xiao Jun Deng

Appl. Phys. Lett. 61, 2560 (1992); http://dx.doi.org/10.1063/1.108126 (3 pages) | Cited 15 times

Full Text: | Download PDF

Show Abstract
We report the observation of higher diffusivity of hydrogen in some solar cell silicon compared to that in Czochralski and float zone wafers. SIMS profiles of hydrogen/deuterium, implanted at low energies and in a temperature range of 100–300 °C, are compared for a variety of different types of silicon substrates. In addition, a new technique that utilizes hydrogen decoration of dislocations was applied to directly verify long diffusion depths in some solar cell silicon. Higher diffusivity of hydrogen permits backside hydrogenation of solar cells to be carried out in less than 30 min with a significant improvement in the cell performance.
Show PACS
66.30.J- Diffusion of impurities
61.72.uf Ge and Si
84.60.Jt Photoelectric conversion

Efficient visible electroluminescence from highly porous silicon under cathodic bias

L. T. Canham, W. Y. Leong, M. I. J. Beale, T. I. Cox, and L. Taylor

Appl. Phys. Lett. 61, 2563 (1992); http://dx.doi.org/10.1063/1.108127 (3 pages) | Cited 74 times

Full Text: | Download PDF

Show Abstract
Visible electroluminescence (EL) has been obtained from porous silicon cathodically biased in an aqueous electrolyte containing either the persulphate or the peroxide ion. EL efficiencies of up to 0.1% have been obtained from porous silicon formed on both n‐type and p‐type substrates for the application of only a few volts bias. In subdued lighting, the EL is easily visible to the naked eye at excitation densities of 0.1 W cm−2. EL is obtained only from porous silicon capable of giving photoluminescence (PL); the EL and PL spectra are broadly similar in width and peak wavelength. The EL spectra are reversibly shifted to shorter wavelengths as the magnitude of the bias is increased. In contrast with the previously reported EL under anodic conditions, this cathodic EL process does not irreversibly oxidize the porous silicon skeleton.
Show PACS
78.60.Fi Electroluminescence
78.55.Hx Other solid inorganic materials

Si band‐gap shrinkage caused by local strain at Si/SiO2 edge

Kan Takeuchi and Masakazu Aoki

Appl. Phys. Lett. 61, 2566 (1992); http://dx.doi.org/10.1063/1.108128 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
This letter describes Si band‐gap shrinkage caused by local strain at the local oxidation of silicon (LOCOS) edge. The local band‐gap shrinkage of 20–30 meV is shown to exist at the LOCOS edge by measuring the forward‐biased junction current of square n+ regions on a p substrate for various junction sizes. The junction current is observed to be proportional to the peripheral length rather than the area of the square n+ regions at liquid‐nitrogen temperatures. It is also likely that the shrinkage would degrade the current gain of bipolar transistors, especially at low temperatures.  
Show PACS
85.30.De Semiconductor-device characterization, design, and modeling
73.20.At Surface states, band structure, electron density of states
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Spin‐dependent effects in porous silicon

M. S. Brandt and M. Stutzmann

Appl. Phys. Lett. 61, 2569 (1992); http://dx.doi.org/10.1063/1.108129 (3 pages) | Cited 52 times

Full Text: | Download PDF

Show Abstract
Luminescent anodically etched porous silicon is studied with electron spin resonance, optically detected magnetic resonance, and spin‐dependent photoconductivity. The Pb center, the silicon dangling bond at the crystalline Si/SiO2 interface, is found to be the dominant paramagnetic defect, influencing both photoconductivity and photoluminescence. The assignment is supported by the observation of the corresponding 29Si hyperfine lines. A second hyperfine split pair is attributed to Si‐F complexes formed during the etching process and remaining in the porous material.
Show PACS
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
72.40.+w Photoconduction and photovoltaic effects
78.55.Hx Other solid inorganic materials
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close