Chemical Beam Epitaxy (CBE) and Laser-Enhanced CBE of GaAs Using Tris-Dimethylaminoarsenic

1994 ◽  
Vol 340 ◽  
Author(s):  
H. K. Dong ◽  
N. Y. Li ◽  
C. W. Tu ◽  
M. Geva ◽  
W. C. Mitchel
Keyword(s):  
Substrate Temperature ◽  
Electron Mobility ◽  
Doping Concentration ◽  
Growth Enhancement ◽  
Chemical Beam Epitaxy ◽  
Unintentional Doping ◽  
P Type ◽  
First Time ◽  
Substrate Temperatures ◽  
Type Conduction

ABSTRACTIn this paper, we report chemical beam epitaxy (CBE) of GaAs, and for the first time, Arion laser-assisted CBE using triethylgallium (TEGa) and tris-dimethylaminoarsenic (TDMAAs), a safer alternative to arsine. Samples grown at substrate temperatures above 490° C show n-type conduction, while those grown at lower temperatures show p-type conduction. An unintentional doping concentration of n∼lx1016 cm-3 with an electron mobility of 5200 cm2/V.s at 300 K and 16000 cm2/V.s at 77 K have been achieved. These are the best results reported for GaAs grown with TDMAAs. Laser-assisted CBE of GaAs is studied in the substrate temperature range of 240-550°C. There are two different substrate-temperature regions for laser-enhanced growth, 265 to 340°C and 340 to 440°C, which are believed to be caused by different TEGa decomposition mechanisms. The laser-assisted growth with TDMAAs, compared to AS4 or AsH3, shows a wider range of growth enhancement at low substrate temperatures.

scholarly journals Morphology and electrical characteristics of p-type ZnO microwires with zigzag rough surfaces induced by Sb doping

RSC Advances ◽  
2018 ◽  
Vol 8 (61) ◽  
pp. 35023-35030 ◽  
Author(s):  
Linlin Shi ◽  
Luchao Du ◽  
Yingtian Xu ◽  
Liang Jin ◽  
He Zhang ◽  
...  
Keyword(s):  
Rough Surface ◽  
Doping Concentration ◽  
Rough Surfaces ◽  
Electrical Characteristics ◽  
Sb Doping ◽  
P Type ◽  
Type Conduction

Sb-doped microwires which have a zigzag rough surface demonstrate p-type conduction and enhanced rectifying behavior with increasing Sb doping concentration.

Conductivity Control of AlGaN. Fabrication of AlGaN/GaN Multi-Heterośtructure and their Application to UV/Blue Light Emitting Devices

1992 ◽  
Vol 242 ◽  
Author(s):  
I. Akasaki ◽  
H. Amano
Keyword(s):  
Electrical Properties ◽  
Size Effect ◽  
High Quality ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Quantum Size ◽  
Junction Type ◽  
P Type ◽  
First Time ◽  
Type Conduction

ABSTRACTThe method for controlling the electrical properties of n-type GaN and AIGaN have been established. Both GaN and AIGaN films having p - type conduction have been realized for the first time. High quality AIGaN/GaN mu I t i-he t er ostrueture showing clear quantum size effect has been fabricated. P-n junction type UV/blue LED with double he t e ros t rue ture have been developed for the first time.

Diffusion and annealing effects of crystalline CuInSe2

1985 ◽  
Vol 63 (6) ◽  
pp. 811-814 ◽  
Author(s):  
A. Vahid Shahidi ◽  
I. Shih ◽  
C. H. Champness
Keyword(s):  
Freezing Method ◽  
Annealing Effects ◽  
P Type ◽  
Directional Freezing ◽  
First Time ◽  
Annealing Experiments ◽  
Type Conduction

Diffusion and annealing experiments have been made on p-type monocrystalline CuInSe2 samples grown by the directional freezing method. It was found that tellurium diffusion into CuInSe2 produced p-type conduction whereas bismuth diffusion resulted in n-type conduction. Photoconductivity experiments were also made for the first time at 77 K on p-type monocrystalline CuInSe2 samples.

Effects of Laser Irradiation on Growth and Doping Characteristics of GaAs in Chemical Beam Epitaxy

1995 ◽  
Vol 388 ◽  
Author(s):  
H. K. Dong ◽  
N. Y. Li ◽  
C. W. Tu
Keyword(s):  
Laser Irradiation ◽  
Hole Concentration ◽  
Growth Enhancement ◽  
Chemical Beam Epitaxy ◽  
Silicon Doping ◽  
Gaas Films ◽  
Ion Laser ◽  
Temperature Window ◽  
Substrate Temperatures ◽  
Incorporation Ratio

AbstractIn this paper, we report laser-assisted chemical beam epitaxy (CBE) of GaAs using triethylgallium (TEGa), tris-dimethylaminoarsenic (TDMAAs), and an ar ion laser operating at visible or ultraviolet (UV) wavelength. the laser-assisted growth with TDMAAs, compared to as4 or asH3, shows a wider range of growth enhancement at low substrate temperatures. Unlike CBE of GaAs without laser irradiation, laser-enhanced GaAs growth rate was found to be constant as the V/III incorporation ratio changes. by using diiodomethane (CI2H2) as a dopant gas, the GaAs films with laser irradiation show a much higher hole concentration than those grown simultaneously without laser irradiation at substrate temperatures from 460-530°C. Laser irradiation was also found to enhance silicon incorporation at low temperatures. Photothermal effects are responsible for laser-enhanced growth and silicon doping, but the wider temperature window in laser-enhanced growth and the laser-enhanced carbon incorporation are caused by additional photocatalytic or photochemical effects.

Observations on the growth of barium bismuth oxide thin films

1992 ◽  
Vol 50 (1) ◽  
pp. 76-77
Author(s):  
M G. Norton ◽  
E.S. Hellman ◽  
E.H. Hartford ◽  
C.B. Carter
Keyword(s):  
Substrate Temperature ◽  
Deposition Process ◽  
Nucleation Layer ◽  
Second Stage ◽  
Device Applications ◽  
High Transition ◽  
Substrate Temperatures ◽  
Oriented Material ◽  
Barium Bismuth ◽  
Superconductor Device

The bismuthates (for example, Ba1-xKxBiO3) represent a class of high transition temperature superconductors. The lack of anisotropy and the long coherence length of the bismuthates makes them technologically interesting for superconductor device applications. To obtain (100) oriented Ba1-xKxBiO3 films on (100) oriented MgO, a two-stage deposition process is utilized. In the first stage the films are nucleated at higher substrate temperatures, without the potassium. This process appears to facilitate the formation of the perovskite (100) orientation on (100) MgO. This nucleation layer is typically between 10 and 50 nm thick. In the second stage, the substrate temperature is reduced and the Ba1-xKxBiO3 is grown. Continued growth of (100) oriented material is possible at the lower substrate temperature.

scholarly journals Optimization of Sb2S3 Nanocrystal Concentrations in P3HT: PCBM Layers to Improve the Performance of Polymer Solar Cells

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2152
Author(s):  
E. M. Mkawi ◽  
Y. Al-Hadeethi ◽  
R. S. Bazuhair ◽  
A. S. Yousef ◽  
E. Shalaan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Doping Concentration ◽  
Polymer Solar Cells ◽  
Energy Levels ◽  
Acid Methyl Ester ◽  
Visible Absorption ◽  
Block Polymer ◽  
Coating Method ◽  
Electronic Parameters ◽  
P Type

In this study, polymer solar cells were synthesized by adding Sb2S3 nanocrystals (NCs) to thin blended films with polymer poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) as the p-type material prepared via the spin-coating method. The purpose of this study is to investigate the dependence of polymer solar cells’ performance on the concentration of Sb2S3 nanocrystals. The effect of the Sb2S3 nanocrystal concentrations (0.01, 0.02, 0.03, and 0.04 mg/mL) in the polymer’s active layer was determined using different characterization techniques. X-ray diffraction (XRD) displayed doped ratio dependences of P3HT crystallite orientations of P3HT crystallites inside a block polymer film. Introducing Sb2S3 NCs increased the light harvesting and regulated the energy levels, improving the electronic parameters. Considerable photoluminescence quenching was observed due to additional excited electron pathways through the Sb2S3 NCs. A UV–visible absorption spectra measurement showed the relationship between the optoelectronic properties and improved surface morphology, and this enhancement was detected by a red shift in the absorption spectrum. The absorber layer’s doping concentration played a definitive role in improving the device’s performance. Using a 0.04 mg/mL doping concentration, a solar cell device with a glass /ITO/PEDOT:PSS/P3HT-PCBM: Sb2S3:NC/MoO3/Ag structure achieved a maximum power conversion efficiency of 2.72%. These Sb2S3 NCs obtained by solvothermal fabrication blended with a P3HT: PCBM polymer, would pave the way for a more effective design of organic photovoltaic devices.

The Effect of Doping Concentration and Conductivity Type on Preferential Etching of 4H-SiC by Molten KOH

2004 ◽  
Vol 815 ◽  
Author(s):  
Ying Gao ◽  
Zehong Zhang ◽  
Robert Bondokov ◽  
Stanislav Soloviev ◽  
Tangali Sudarshan
Keyword(s):  
Thermal Diffusion ◽  
Basal Plane ◽  
Doping Concentration ◽  
Structural Defects ◽  
Etch Pits ◽  
Conductivity Type ◽  
Isotropic Etching ◽  
Electrochemical Processes ◽  
P Type ◽  
Koh Etching

AbstractMolten KOH etchings were implemented to delineate structural defects in the n- and ptype 4H-SiC samples with different doping concentrations. It was observed that the etch preference is significantly influenced by both the doping concentrations and the conductivity types. The p-type Si-face 4H-SiC substrate has the most preferential etching property, while it is least for n+ samples. It has been clearly demonstrated that the molten KOH etching process involves both chemical and electrochemical processes, during which isotropic etching and preferential etching are competitive. The n+ 4H-SiC substrate was overcompensated via thermal diffusion of boron to p-type and followed by molten KOH etching. Three kinds of etch pits corresponding to threading screw, threading edge, and basal plane dislocations are distinguishably revealed. The same approach was also successfully employed in delineating structural defects in (0001) C-face SiC wafers.

Properties of carbon films deposited by pulsed laser vaporization from pyrolytic graphite

1989 ◽  
Vol 4 (5) ◽  
pp. 1238-1242 ◽  
Author(s):  
A. P. Malshe ◽  
S. M. Chaudhari ◽  
S. M. Kanetkar ◽  
S. B. Ogale ◽  
S. V. Rajarshi ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Pyrolytic Graphite ◽  
Carbon Films ◽  
Laser Vaporization ◽  
Film Properties ◽  
Amorphous Carbon Films ◽  
Resistivity Measurements ◽  
Laser Raman ◽  
Quartz Substrates ◽  
Substrate Temperatures

Amorphous carbon films have been deposited on silicon 〈111〉 and quartz substrates by pulsed ruby laser vaporization from pyrolytic graphite. Depositions have been carried out at different substrate temperatures, and the properties of the deposited carbon films have been studied using IR and UV–VIS transmission, ellipsometry, and laser-Raman spectroscopies. Chemical and electrical resistivity measurements have also been performed. It is shown that the film properties depend critically on the substrate temperature and that at the substrate temperature of 50 °C films with substantial proportion of sp3 hybridized orbitals are obtained.

scholarly journals Simulation of Mechanical Deformation and Tribology of Nano-Thin Amorphous Hydrogenated Carbon (a:Ch) Films Using Molecular Dynamics

1996 ◽  
Vol 436 ◽  
Author(s):  
J. N. Glosli ◽  
M. R. Philpott ◽  
J. Belak
Keyword(s):  
Molecular Dynamics ◽  
Substrate Temperature ◽  
Computer Simulations ◽  
Mechanical Deformation ◽  
Porous Graphite ◽  
Pure Carbon ◽  
Substrate Temperatures ◽  
Amorphous Hydrogenated Carbon ◽  
Deposition Energy

AbstractMolecular dynamics computer simulations are used to study the effect of substrate temperature on the microstructure of deposited amorphous hydrogenated carbon (a:CH) films. A transition from dense diamond-like films to porous graphite-like films is observed between substrate temperatures of 400K and 600K for a deposition energy of 20 eV. The dense a:CH film grown at 300K and 20 eV has a hardness (˜50 GPa) about half that of a pure carbon (a:C) film grown under the same conditions.

12 kV 4H-SiC p-IGBTs with Record Low Specific On-Resistance

2008 ◽  
Vol 600-603 ◽  
pp. 1187-1190 ◽  
Author(s):  
Q. Jon Zhang ◽  
Charlotte Jonas ◽  
Joseph J. Sumakeris ◽  
Anant K. Agarwal ◽  
John W. Palmour
Keyword(s):  
Carrier Lifetime ◽  
Drift Region ◽  
Gate Bias ◽  
Enhancement Layer ◽  
Channel Mobility ◽  
Dc Characteristics ◽  
Blocking Voltage ◽  
High Carrier ◽  
P Type ◽  
First Time

DC characteristics of 4H-SiC p-channel IGBTs capable of blocking -12 kV and conducting -0.4 A (-100 A/cm2) at a forward voltage of -5.2 V at 25°C are demonstrated for the first time. A record low differential on-resistance of 14 mW×cm2 was achieved with a gate bias of -20 V indicating a strong conductivity modulation in the p-type drift region. A moderately doped current enhancement layer grown on the lightly doped drift layer effectively reduces the JFET resistance while maintains a high carrier lifetime for conductivity modulation. A hole MOS channel mobility of 12.5 cm2/V-s at -20 V of gate bias was measured with a MOS threshold voltage of -5.8 V. The blocking voltage of -12 kV was achieved by Junction Termination Extension (JTE).

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