Electro-Optical Studies of Vanadium in GaP by Space Charge Spectroscopies

1992 ◽  
Vol 261 ◽  
Author(s):  
Georges Bremond ◽  
G. Guillot ◽  
P. Roura ◽  
W. Ulrici
Keyword(s):  
Optical Absorption ◽  
Deep Level ◽  
Donor Level ◽  
Complete Understanding ◽  
Optical Studies ◽  
Electrical And Optical Properties ◽  
Related Donor ◽  
Type V ◽  
P Type ◽  
Level Identification

ABSTRACTA complete understanding of the electrical and optical properties of the Vanadium related donor level (VGa3+/VGa4+) in GaP is deduced from a number of different characterization techniques (deep level transient and deep level optical spectroscopies, optical absorption) performed on p-type V doped GaP. The VGa3+/VGa4+ donor level is located at Ev+0.25eV. This assignment is based on the correlation of optical absorption spectra and the photoneutralization cross-section σp°(hv) curve obtained by deep level optical spectroscopy confirming that this technique is very unique for deep level identification in semiconductor materials.

Deep Level Related Yellow Luminescence in P-Type GaN Grown by MBE on (0001) Sapphire

1999 ◽  
Vol 595 ◽  
Author(s):  
Giancarlo Salviati ◽  
Nicola Armani ◽  
Carlo Zanotti-Fregonara ◽  
Enos Gombia ◽  
Martin Albrecht ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Deep Level ◽  
Cubic Phase ◽  
Donor Level ◽  
Yellow Luminescence ◽  
Wurtzite Phase ◽  
Shallow Acceptor ◽  
Deep Donor ◽  
P Type ◽  
Deep Donor Level

AbstractYellow luminescence (YL) has been studied in GaN:Mg doped with Mg concentrations ranging from 1019 to 1021 cm−3 by spectral CL (T=5K) and TEM and explained by suggesting that a different mechanism could be responsible for the YL in p-type GaN with respect to that acting in n-type GaN.Transitions at 2.2, 2.8, 3.27, 3.21, and 3.44 eV were found. In addition to the wurtzite phase, TEM showed a different amount of the cubic phase in the samples. Nano tubes with a density of 3×109 cm−2 were also observed by approaching the layer/substrate interface. Besides this, coherent inclusions were found with a diameter in the nm range and a volume fraction of about 1%.The 2.8 eV transition was correlated to a deep level at 600 meV below the conduction band (CB) due to MgGa-VN complexes. The 3.27 eV emission was ascribed to a shallow acceptor at about 170-190 meV above the valence band (VB) due to MgGa.The 2.2 eV yellow band, not present in low doped samples, increased by increasing the Mg concentration. It was ascribed to a transition between a deep donor level at 0.8-1.1 eV below the CB edge due to NGa and the shallow acceptor due to MgGa. This assumption was checked by studying the role of C in Mg compensation. CL spectra from a sample with high C content showed transitions between a C-related 200 meV shallow donor and a deep donor level at about 0.9- 1.1 eV below the CB due to a NGa-VN complex. In our hypothesis this should induce a decrease of the integrated intensity in both the 2.2 and 2.8 eV bands, as actually shown by CL investigations.

scholarly journals Deep level related yellow luminescence in p-type GaN grown by MBE on (0001) sapphire

2000 ◽  
Vol 5 (S1) ◽  
pp. 754-760
Author(s):  
Giancarlo Salviati ◽  
Nicola Armani ◽  
Carlo Zanotti-Fregonara ◽  
Enos Gombia ◽  
Martin Albrecht ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Deep Level ◽  
Cubic Phase ◽  
Donor Level ◽  
Yellow Luminescence ◽  
Wurtzite Phase ◽  
Shallow Acceptor ◽  
Deep Donor ◽  
P Type ◽  
Deep Donor Level

Yellow luminescence (YL) has been studied in GaN:Mg doped with Mg concentrations ranging from 1019 to 1021 cm-3 by spectral CL (T=K) and TEM and explained by suggesting that a different mechanism could be responsible for the YL in p-type GaN with respect to that acting in n-type GaN.Transitions at 2.2, 2.8, 3.27, 3.21, and 3.44 eV were found. In addition to the wurtzite phase, TEM showed a different amount of the cubic phase in the samples. Nano tubes with a density of 3×109 cm−2 were also observed by approaching the layer/substrate interface. Besides this, coherent inclusions were found with a diameter in the nm range and a volume fraction of about 1%.The 2.8 eV transition was correlated to a deep level at 600 meV below the conduction band (CB) due to MgGa-VN complexes. The 3.27 eV emission was ascribed to a shallow acceptor at about 170-190 meV above the valence band (VB) due to MgGa.The 2.2 eV yellow band, not present in low doped samples, increased by increasing the Mg concentration. It was ascribed to a transition between a deep donor level at 0.8-1.1 eV below the CB edge due to NGa and the shallow acceptor due to MgGa. This assumption was checked by studying the role of C in Mg compensation. CL spectra from a sample with high C content showed transitions between a C-related 200 meV shallow donor and a deep donor level at about 0.9-1.1 eV below the CB due to a NGa-VN complex. In our hypothesis this should induce a decrease of the integrated intensity in both the 2.2 and 2.8 eV bands, as actually shown by CL investigations.

Effect of Fast Electron Irradiation on Electrical and Optical Properties of CdGeAs2 and ZnGep2

1999 ◽  
Vol 607 ◽  
Author(s):  
I. Zwieback ◽  
J. Maffetone ◽  
D. Perlov ◽  
J. Harper ◽  
W. Ruderman ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Optical Properties ◽  
Optical Absorption ◽  
Electron Irradiation ◽  
Fast Electron ◽  
Optical Transmission ◽  
Electrical And Optical Properties ◽  
Electron Dose ◽  
P Type ◽  
Higher Doses

AbstractWe report on the effects of fast electron irradiation on the optical absorption (α) of CdGeAs2and ZnGeP2 and on the electrical properties of CdGeAs2. In p-CdGeAs2 irradiation led to the reduction in α and an increase in the electrical resistivity. The lowest values of α (about 0.1 cm' at 5µm<λ<10µm) were obtained on irradiated crystals of p-type with the highest degree of compensation. Further accumulation of the electron dose caused conversion to n-type and deterioration of the optical transmission. In ZnGeP2 irradiation caused a decrease in a at λ>0.85 λm and increase in α at λ<0.85 μm. At λ=2.05 μm, α for the o-ray could be reduced to less than 0.08 cm−1. At higher doses, saturation in α was observed. The effects of irradiation are discussed in connection with possible mechanisms of optical absorption in CdGeAs2 and ZnGeP2.

Spectrum of Defect States in Porous Organic Low-k Dielectric Films, Annealed in Argon and Nitrogen

2003 ◽  
Vol 766 ◽  
Author(s):  
V. Ligatchev ◽  
T.K.S. Wong ◽  
T.K. Goh ◽  
Rusli Suzhu Yu
Keyword(s):  
Deep Level ◽  
Dielectric Films ◽  
Silicon Substrates ◽  
Reverse Bias Voltage ◽  
Defect States ◽  
Single Side ◽  
Sandwich Type ◽  
Transient Spectroscopy ◽  
P Type ◽  
Spectrum Deconvolution

AbstractDefect spectrum N(E) of porous organic dielectric (POD) films is studied with capacitance deep-level-transient-spectroscopy (C-DLTS) in the energy range up to 0.7 eV below conduction band bottom Ec. The POD films were prepared by spin coating onto 200mm p-type (1 – 10 Δcm) single-side polished silicon substrates followed by baking at 325°C on a hot plate and curing at 425°C in furnace. The film thickness is in the 5000 – 6000 Å range. The ‘sandwich’ -type NiCr/POD/p-Si/NiCr test structures showed both rectifying DC current-voltage characteristics and linear 1/C2 vs. DC reverse bias voltage. These confirm the applicability of the C-DLTS technique for defect spectrum deconvolution and the n-type conductivity of the studied films. Isochronal annealing (30 min in argon or 60 min in nitrogen) has been performed over the temperature range 300°C - 650°C. The N(E) distribution is only slightly affected by annealing in argon. However, the distribution depends strongly on the annealing temperature in nitrogen ambient. A strong N(E) peak at Ec – E = 0.55 – 0.60 eV is detected in all samples annealed in argon but this peak is practically absent in samples annealed in nitrogen at Ta < 480°C. On the other hand, two new peaks at Ec – E = 0.12 and 0.20 eV appear in the N(E) spectrum of the samples annealed in nitrogen at Ta = 650°C. The different features of the defect spectrum are attributed to different interactions of argon and nitrogen with dangling carbon bonds on the intra-pore surfaces.

scholarly journals Comparison of deep level spectra in p-type and n-type GaN grown by molecular beam epitaxy [phys. stat. sol. (b) 244, No. 6, 1867–1871 (2007)]

2007 ◽  
Vol 244 (12) ◽  
pp. 4692-4692
Author(s):  
A. Armstrong ◽  
A. Corrion ◽  
C. Poblenz ◽  
U. K. Mishra ◽  
J. S. Speck ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Deep Level ◽  
P Type

Electrical and Optical Properties of Vanadium in Omvpe-Grown GaAs

1989 ◽  
Vol 145 ◽  
Author(s):  
W. S. Hobson ◽  
S. J. Pearton ◽  
V. Swaminathan ◽  
A. S. Jordan ◽  
Y. J. Kao ◽  
...  
Keyword(s):  
Deep Level ◽  
Vanadium Content ◽  
Epitaxial Layers ◽  
Electrical And Optical Properties ◽  
Vanadium Concentration ◽  
Co Doping ◽  
Undoped Material ◽  
Maximum Value ◽  
Si Doped ◽  
Transient Spectroscopy

AbstractThe electrical and photoluminescent properties of vanadium incorporated into GaAs epitaxial layers from a VO(OC2 H5)3 source during organometallic vapor phase epitaxy were examined. The vanadium concentration in the GaAs was controllably varied from 1016 to 1018 atoms cm−3. Deep level transient spectroscopy showed the presence of an electron trap at Ec – 0.15 eV which increased in concentration with vanadium content of the epitaxial layers. A maximum value of 8 × 1015 cm−3 for this trap was obtained. There were no midgap electron traps associated with vanadium. In intentionally Si-doped epitaxial layers, co-doping with vanadium was observed to have no effect in reducing the carrier density when the Si concentration was > 4 × 1016 cm−3. The net carrier concentration profiles resulting from 29 si implantation into GaAs containing 1018 cm−3of total V had sharper tails than for similar implantation into undoped material, indicating the presence of less than 1016 cm−3V-related acceptors. Photoluminescent spectra exhibited the characteristic V+3intracenter emission at 0.65∼0.75 eV. No other deep level photoluminescence was detected. For a V concentration of 1016 cm−3only 2.5 × 1013 cm−3was electrically active. Over the entire V concentration investigated this impurity was predominantly (≥99%) inactive.

Optical Studies of porous Silicon

1993 ◽  
Vol 298 ◽  
Author(s):  
T. Lin ◽  
M. E. Sixta ◽  
J. N. Cox ◽  
M. E. Delaney
Keyword(s):  
Optical Properties ◽  
Fourier Transform ◽  
Steady State ◽  
Porous Silicon ◽  
Ftir Spectroscopy ◽  
Optical Studies ◽  
Etched Silicon ◽  
Bending Modes ◽  
P Type ◽  
Over Time

AbstractThe optical properties of both electrochemically anodized and chemically stain-etched porous silicon are presented. Fourier transform infrared (FTIR) spectroscopy showed that absorbance in stain-etched samples was 3x and 1.7x greater than in anodized samples for the SiH/SiH2 stretch and scissors-bending modes, respectively. Also, oxygen is detected in stain-etched samples immediately after formation, unlike anodized samples. Photoluminescence measurements showed different steady state characteristics. Electrochemical-etched silicon samples stored in air increased in photoluminescent intensity over time, unlike the stain-etched samples. A photoluminescent device made by anodization on epitaxial p-type material (0.4 Ωm) on n-type substrate (0.1 Ω-cm) did not exhibit electroluminescence.

scholarly journals Improve the performance of solar cells using new designs for pelvic center wheel Type V compound mirrors encased by Vernil glasses

2006 ◽  
Vol 3 (4) ◽  
pp. 586-590
Author(s):  
Baghdad Science Journal
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Cooling System ◽  
Type V ◽  
P Type

Design and build a center basins new p-type four mirrors were studied its effect on all parameters evaluating the performance of the solar cell silicon in the absence of a cooling system is switched on and noted that the efficiency of the performance Hzzh cell increased from 11.94 to 21 without cooling either with cooling has increased the efficiency of the

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