Recombination and Electronic Transport in Low-Gap a-Si,Ge:H,F Alloys

1987 ◽  
Vol 95 ◽  
Author(s):  
S. Aljishi ◽  
D. S. Shen ◽  
V. Chu ◽  
Z E. Smith ◽  
J. P. Conde ◽  
...  
Keyword(s):  
Conduction Band ◽  
Electronic Transport ◽  
Room Temperature ◽  
Dark Conductivity ◽  
Electron Trapping ◽  
Conduction Band Edge ◽  
Band Tail ◽  
Intensity Dependence ◽  
Defect Densities ◽  
Deposition Conditions

AbstractWe have studied the temperature and intensity dependence (130K to 300K) of photo- and dark conductivity in a series of low-gap a-Si,Ge:H,F alloys (Eopt=1.25 to 1.33 eV) prepared under different deposition conditions. Electron time of flight experiments were conducted between 300K and 400K. Results reveal an increase in the slope of the exponential conduction band tail to ∼ 50 meV and a peak in electron trapping states at 0.3 to 0.4 eV below the conduction band edge, leading to a transition from extended to hopping conduction by electrons at slightly below room temperature. The alloys have midgap defect densities in the low 1017 cm−3eV−1 range.

Electronic Transport Properties of a-Si:H,F/a-Si,Ge:H,F Superlattices

1987 ◽  
Vol 95 ◽  
Author(s):  
J. P. Conde ◽  
S. Aljishi ◽  
D. S. Shen ◽  
V. Chu ◽  
Z E. Smith ◽  
...  
Keyword(s):  
Barrier Layer ◽  
Electronic Transport ◽  
Thermal Emission ◽  
Parallel Transport ◽  
Dark Conductivity ◽  
Alloy Layer ◽  
Conductivity Activation Energy ◽  
Superlattice Structures ◽  
Deposition Conditions ◽  
Extract Information

AbstractWe study the dark conductivity σd, dark conductivity activation energy Ea and photoconductivity σph of a-Si:H,F/a-Si,Ge:H,F superlattices both perpendicular and parallel to the plane of the layers. In parallel transport, both the σph and σd are dominated by the alloy layer characteristics with the superposition of carrier confinement quantum effects. In perpendicular transport, the σd shows an interplay of quantum mechanical tunneling through the barriers and of classical thermal emission over the barrier layer and the σph is controlled by the decreasing absorption by the silicon barrier layer as the optical gap Eopt of the structure decreases.We also found that the multilayer structure allows to grow lower gap a-Si,Ge:H,F alloys than achievable under the same deposition conditions for bulk materials. This stabilizing effect allowed us to study low-gap superlattice structures and extract information about these very low gap (<1.2 eV) a- Si,Ge:H,F alloys.

Hydrogenation of Gallium Nitride

1993 ◽  
Vol 325 ◽  
Author(s):  
M. S. Brandt ◽  
N. M. Johnson ◽  
R. J. Molnar ◽  
R. Singh ◽  
T. D. Moustakas
Keyword(s):  
Comparative Study ◽  
Conduction Band ◽  
Room Temperature ◽  
Hole Concentration ◽  
Conduction Band Edge ◽  
Order Of Magnitude ◽  
Si Doped ◽  
Donor State ◽  
P Type ◽  
Mg Doped

AbstractA comparative study of the effects of hydrogen in n-type (unintentionally and Si-doped) as well as p-type (Mg-doped) MBE-grown GaN is presented. Hydrogenation above 500°C reduces the hole concentration at room temperature in the p-type material by one order of magnitude. Three different microscopic effects of hydrogen are suggested: Passivation of deep defects and of Mg-acceptors due to formation of hydrogen-related complexes and the introduction of a hydrogenrelated donor state 100 meV below the conduction band edge.

SiO2/SiC Interface Properties on Various Surface Orientations

2002 ◽  
Vol 742 ◽  
Author(s):  
Hiroshi Yano ◽  
Taichi Hirao ◽  
Tsunenobu Kimoto ◽  
Hiroyuki Matsunami
Keyword(s):  
Conduction Band ◽  
Room Temperature ◽  
Interface State ◽  
State Density ◽  
Interface State Density ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Interface Properties ◽  
Mos Capacitors ◽  
Channel Mobility

ABSTRACTThe interface properties of MOS capacitors and MOSFETs were characterized using the (0001), (1120), and (0338) faces of 4H-SiC. (0001) and (1120) correspond to (111) and (110) in cubic structure. (0338) is semi-equivalent to (100). The interface states near the conduction band edge are discussed based on the capacitance and conductance measurements of n-type MOS capacitors at a low temperature and room temperature. The (0338) face indicated the smallest interface state density near the conduction band edge and highest channel mobility in n-channel MOSFETs among these faces.

Determination of conduction band tail and Fermi energy of heavily Si‐doped GaAs by room‐temperature photoluminescence

1995 ◽  
Vol 78 (5) ◽  
pp. 3367-3370 ◽  
Author(s):  
Nam‐Young Lee ◽  
Kyu‐Jang Lee ◽  
Chul Lee ◽  
Jae‐Eun Kim ◽  
Hae Yong Park ◽  
...  
Keyword(s):  
Conduction Band ◽  
Fermi Energy ◽  
Room Temperature ◽  
Band Tail ◽  
Room Temperature Photoluminescence ◽  
Si Doped

scholarly journals The Influence of Deposition Conditions on Structural Properties of PbI2

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Ali M. Mousa ◽  
Natheer J. Al-rubaie
Keyword(s):  
Electrical Properties ◽  
Grain Boundaries ◽  
Structural Properties ◽  
Room Temperature ◽  
Dark Conductivity ◽  
Gain Factor ◽  
The Other ◽  
Light Illumination ◽  
Free Carriers ◽  
Deposition Conditions

The effect of deposition environment conditions on the electrical and structural properties of deposited PbI2 layers were studied. The layers were deposited from solution under dark and room light illumination with and without applying magnetic field. XRD, electrical, and photo-electrical properties were measured at room temperature. An increase in the grain size versus the platelet area was noticed.The electrical properties revealed a dependence on deposition conditions. Dark conductivity increases from 1.7×10−10 to 5×10−9 (Ωcm)-1 when deposition was carried out in darkness. A gain factor (the ratio between photoconductivity and dark conductivity) of (23) was obtained. The results indicate that the increase in electrical conductivity is mainly due to the plane 001, where the average number of grain boundaries in this plane sharply decreases when deposition takes place in darkness. On the other hand, the increase in photoconductivity could be due to the decrease in the recombination of free carriers along the grain boundaries.

scholarly journals Lateral PbS Photovoltaic Devices for High Performance Infrared and Terahertz Photodetectors

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1692
Author(s):  
Emmanuel K. Ampadu ◽  
Jungdong Kim ◽  
Eunsoon Oh
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Photovoltaic Device ◽  
Photovoltaic Devices ◽  
Temperature Spectrum ◽  
Terahertz Region ◽  
Room Temperature Spectrum ◽  
Ftir Spectrometer ◽  
Titanium Substrates ◽  
Deposition Conditions

We fabricated a lateral photovoltaic device for use as infrared to terahertz (THz) detectors by chemically depositing PbS films on titanium substrates. We discussed the material properties of PbS films grown on glass with varying deposition conditions. PbS was deposited on Ti substrates and by taking advantage of the Ti/PbS Schottky junction, we discussed the photocurrent transients as well as the room temperature spectrum response measured by Fourier transform infrared (FTIR) spectrometer. Our photovoltaic PbS device operates at room temperature for wavelength ranges up to 50 µm, which is in the terahertz region, making the device highly applicable in many fields.

Electrons in feldspar II: a consideration of the influence of conduction band-tail states on luminescence processes

2002 ◽  
Vol 29 (3) ◽  
pp. 217-225 ◽  
Author(s):  
N. R. J. Poolton ◽  
K. B. Ozanyan ◽  
J. Wallinga ◽  
A. S. Murray ◽  
L. Bøtter-Jensen
Keyword(s):  
Conduction Band ◽  
Band Tail
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