Photothermal ionization spectroscopy of selectively boron-doped GexSi(1–x)Si strained-layer heterostructures

1989 ◽  
Vol 67 (4) ◽  
pp. 321-325 ◽  
Author(s):  
H. F. Jang ◽  
W. R. Datars ◽  
T. Timusk ◽  
A. A. Berezin ◽  
D. C. Houghton
Keyword(s):  
Dominant Role ◽  
High Mobility ◽  
Hole Mobility ◽  
Far Infrared ◽  
Experimental Conditions ◽  
Strained Layer ◽  
Boron Doped ◽  
Photothermal Ionization ◽  
Photothermal Ionization Spectroscopy ◽  
Sheet Charge

Far-infrared photothermal ionization spectroscopy has been used to investigate the impurities in selectively boron-doped GexSi(1–x)–Si strained-layer heterostructures. The spectra are obtained under various experimental conditions: with and without band-edge light and by varying the temperature of, and voltage applied to, the sample. The transport properties, resistivity, sheet charge density, and Hall hole mobility of these samples are presented. It is found that a sample with a two-dimensional hole gas (2-DHG) behavior at the GexSi(1–x)–Si interface has a weak photoresponse. This is due to a small number of photo-generated carriers in comparison with the residual hole carriers. For samples that do not show 2-DHG behavior, the photo-response from the substrate plays the dominant role for low applied voltages. At higher voltages, the response from the epitaxial layers becomes evident. The majority impurity is identified as the intentional dopant boron, and the dominant minority impurity is found to be phosphorus. It is concluded that although the free carriers are generated in the heavily B-doped layer, those carriers conducted through the low-energy high-mobility GexSi(1–x)–Si interface dominate the photoresponse.

Far‐infrared photothermal ionization spectroscopy of semiconductors in the presence of intrinsic light

1983 ◽  
Vol 54 (6) ◽  
pp. 3464-3474 ◽  
Author(s):  
M. J. H. van de Steeg ◽  
H. W. H. M. Jongbloets ◽  
J. W. Gerritsen ◽  
P. Wyder
Keyword(s):  
Far Infrared ◽  
Photothermal Ionization ◽  
Photothermal Ionization Spectroscopy

Laser-Thermal Impurity Pumping of Shallow Donors in Ultrapure Germanium

1989 ◽  
Vol 163 ◽  
Author(s):  
T. Theiler ◽  
F. Keilmann ◽  
E. E. Haller
Keyword(s):  
Ground State ◽  
Laser Intensity ◽  
Far Infrared ◽  
Equation Model ◽  
Degree Of Ionization ◽  
Rate Equation Model ◽  
Photothermal Ionization ◽  
Photothermal Ionization Spectroscopy ◽  
Intensity Region ◽  
Critical Intensity

AbstractExtremely narrow far-infrared lines [1] of OH-donors in ultrapure germanium are used to probe the fundamental dynamic processes of impurities. We examine the 1s-2p transition as a function of laser intensity, using photothermal ionization spectroscopy (PTIS) modified by Zeeman tuning with frequency-fixed lasers. We observe a change of the resonance line shape in the intensity region near 10-4 W/cm2. This effect can be quantitatively understood in a rate equation model which shows that at the critical intensity the ground state becomes depleted and the dependence of the recombination on the degree of ionization becomes important. Therefore the critical intensity depends also on compensation.

scholarly journals The Efficient Photocatalytic Degradation of Organic Pollutants on the MnFe2O4/BGA Composite under Visible Light

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1276
Author(s):  
Qian Li ◽  
Xiaoyu Jiang ◽  
Yongfu Lian
Keyword(s):  
Rhodamine B ◽  
Synergetic Effect ◽  
Reaction Rate Constant ◽  
Experimental Conditions ◽  
First Order Kinetics ◽  
Boron Doped ◽  
Fenton Catalyst ◽  
Aerogel Composite ◽  
Doped Graphene ◽  
Apparent Reaction Rate Constant

The MnFe2O4/BGA (boron-doped graphene aerogel) composite was prepared by hydrothermal treatment of MnFe2O4 particles, boric acid, and graphene oxide. When applied as a photo-Fenton catalyst for the degradation of rhodamine B, the MnFe2O4/BGA composite yielded a degradation efficiency much higher than the sum of those of individual MnFe2O4 and BGA under identical experimental conditions, indicating a strong synergetic effect established between MnFe2O4 and BGA. The catalytic degradation of rhodamine B was proved to follow pseudo first-order kinetics, and the apparent reaction rate constant on the MnFe2O4/BGA composite was calculated to be three- and seven-fold that on BGA and MnFe2O4, respectively. Moreover, the MnFe2O4/BGA composite also demonstrated good reusability and could be reused for four cycles without obvious loss of photocatalytic activity.

Far-infrared studies of extremely high mobility gated GaAs/AlGaAs structures in magnetic fields

1998 ◽  
Vol 256-258 ◽  
pp. 481-485 ◽  
Author(s):  
R.J. Heron ◽  
R.A. Lewis ◽  
R.G. Clark ◽  
R.P. Starrett ◽  
B.E. Kane ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
High Mobility ◽  
Far Infrared ◽  
Infrared Studies

High hole mobility in boron doped diamond for power device applications

2009 ◽  
Vol 94 (9) ◽  
pp. 092102 ◽  
Author(s):  
Pierre-Nicolas Volpe ◽  
Julien Pernot ◽  
Pierre Muret ◽  
Franck Omnès
Keyword(s):  
Hole Mobility ◽  
Power Device ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Device Applications

The Influence of the Cell Geometry on the Signal Shape in Electron Drift Velocity Measurements

1986 ◽  
Vol 41 (7) ◽  
pp. 912-920 ◽  
Author(s):  
A. F. Borghesani ◽  
L. Bruschi ◽  
M. Santini ◽  
G. Torzo
Keyword(s):  
Edge Effects ◽  
Accurate Determination ◽  
Finite Size ◽  
High Mobility ◽  
Drift Chamber ◽  
Cell Geometry ◽  
Experimental Conditions ◽  
Drift Cell ◽  
Cell Dimensions

An accurate determination of the “time-of-flight” in swarm experiments with a parallel plate drift chamber requires that the time evolution of the charge induced on the collector is linear. This is obtained in very large chambers where the edge effects can be neglected. However, the experimental conditions of high-mobility carriers and highly pressurized gases impose some constraints on the acceptable drift cell dimensions. We have numerically calculated the effects of the finite size of the collector by exploiting the methods of the images. The numerical results have been experimentally checked using a suitable drift cell of variable geometry. As a result, a quantitative limit on the ratio between the collector radius and the drift distance has been established in order to design drift cells for which the edge effects can be neglected. P.A.C.S. numbers: 2940. 4110 D, 3480 B

Development of III-Sb Technology for p-Channel MOSFETs

2014 ◽  
Vol 23 (03n04) ◽  
pp. 1450015 ◽  
Author(s):  
Andrew Greene ◽  
Shailesh Madisetti ◽  
Michael Yakimov ◽  
Vadim Tokranov ◽  
Serge Oktyabrsky
Keyword(s):  
Quantum Wells ◽  
Supply Voltage ◽  
High Mobility ◽  
Hole Mobility ◽  
State Density ◽  
Injection Velocity ◽  
Oxide Interface ◽  
Group Iii ◽  
Multiple Challenges ◽  
Activation Annealing

Alternative channel materials with superior transport properties over conventional silicon based systems are required for supply voltage scaling in CMOS circuits. Group III- Sb 's are a candidate for high mobility p-channel applications due to a low hole effective mass, large injection velocity in scaled devices and the ability to achieve enhanced hole mobility in strained quantum wells (QW). Multiple challenges in antimonide MOSFET development are assessed and developed technologies were implemented into p-channel MOSFET fabrication with a low thermal processing budget of 350°C. These challenges include growth of “bulk” GaSb and bi-axial compressively strained In x Ga 1-x Sb QW channels on lattice mismatched GaAs substrates, reduction of interface trap state density (Dit) at the III- Sb /high-k oxide interface and avoiding ion implanted source and drain contacts with high temperature activation annealing. A “self-aligned” single mask p-channel MOSFET fabrication process was developed on buried In 0.36 Ga 0.64 Sb QW channels using intermetallic source and drain contacts. The first “gate-last” MOSFET process on In 0.36 Ga 0.64 Sb QW channels with pre-grown epitaxial p++- GaSb contacts is demonstrated. InAs has been proven to be an excellent etch stop layer when using an optimized tetramethylammonium hydroxide (TMAH) etch of p++- GaSb to prevent InGaSb QW damage.

A linear cobalt(II) complex with maximal orbital angular momentum from a non-Aufbau ground state

Science ◽  
2018 ◽  
Vol 362 (6421) ◽  
pp. eaat7319 ◽  
Author(s):  
Philip C. Bunting ◽  
Mihail Atanasov ◽  
Emil Damgaard-Møller ◽  
Mauro Perfetti ◽  
Iris Crassee ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Ground State ◽  
Dominant Role ◽  
Far Infrared ◽  
Wave Number ◽  
Ligand Field ◽  
Electron Configuration ◽  
Susceptibility Data

Orbital angular momentum is a prerequisite for magnetic anisotropy, although in transition metal complexes it is typically quenched by the ligand field. By reducing the basicity of the carbon donor atoms in a pair of alkyl ligands, we synthesized a cobalt(II) dialkyl complex, Co(C(SiMe2ONaph)3)2 (where Me is methyl and Naph is a naphthyl group), wherein the ligand field is sufficiently weak that interelectron repulsion and spin-orbit coupling play a dominant role in determining the electronic ground state. Assignment of a non-Aufbau (dx2–y2, dxy)3(dxz, dyz)3(dz2)1 electron configuration is supported by dc magnetic susceptibility data, experimental charge density maps, and ab initio calculations. Variable-field far-infrared spectroscopy and ac magnetic susceptibility measurements further reveal slow magnetic relaxation via a 450–wave number magnetic excited state.

Contactless Photothermal Ionization Spectroscopy of Shallow Defects in Semiconductors

1993 ◽  
Vol 143-147 ◽  
pp. 1365-1370 ◽  
Author(s):  
Boris A. Andreev ◽  
V.B. Ikonnikov ◽  
E.B. Koslov ◽  
T.M. Lifshits ◽  
V.B. Shmagin
Keyword(s):  
Photothermal Ionization ◽  
Photothermal Ionization Spectroscopy ◽  
Defects In Semiconductors
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