Photoconductivity in some III–V alloys

1970 ◽  
Vol 48 (16) ◽  
pp. 1874-1878 ◽  
Author(s):  
A. E. Taylor ◽  
E. Fortin
Keyword(s):  
Electrical Conductivity ◽  
Optical Absorption ◽  
Band Gap ◽  
Low Temperatures ◽  
Room Temperature ◽  
Alloy Composition ◽  
Energy Gaps ◽  
Sensitivity Curves ◽  
Alloy Concentration ◽  
Absorption Measurements

Photoconducting properties of GaAs–InAs and GaAs–GaSb alloys were investigated at room and low temperatures. The peaks in the photoresponse were found to vary smoothly across the alloy systems. Band gap values obtained from the spectral sensitivity curves confirmed the parabolic variation of energy gaps as a function of the alloy concentration, as previously found in electrical conductivity and optical absorption measurements. The room temperature detectivity of the samples was between 2 × 105 and 8 × 106 cm (Hz)1/2 W−1 for wavelengths varying from 0.8 to 3.5 μ, depending on alloy composition.

Alkali Metal Chalcogenides for Radiation Detection

2011 ◽  
Vol 1341 ◽  
Author(s):  
J. A. Peters ◽  
Zhifu Liu ◽  
B. W. Wessels ◽  
I. Androulakis ◽  
C. P. Sebastian ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Alkali Metal ◽  
Charge Transport ◽  
Band Gap ◽  
Room Temperature ◽  
Gamma Ray ◽  
Radiation Detector ◽  
Radiation Detection ◽  
Charge Carriers ◽  
Metal Chalcogenides

ABSTRACTWe report on the optical and charge transport properties of novel alkali metal chalcogenides, Cs2Hg6S7 and Cs2Cd3Te4, pertaining to their use in radiation detection. Optical absorption, photoconductivity, and gamma ray response measurements for undoped crystals were measured. The band gap energies of the Cs2Hg6S7 and Cs2Cd3Te4 compounds are 1.63 eV and 2.45 eV, respectively. The mobility-lifetime products for charge carriers are of the order of ~10-3 cm2/V for electrons and ~10-4 cm2/V for holes. Detectors fabricated from the ternary compound Cs2Hg6S7 shows well-resolved spectroscopic features at room temperature in response to ϒ -rays at 122 keV from a 57Co source, indicating its potential as a radiation detector.

Optical Absorption of Large Band-Gap SbxBi1-xI3 Alloys

2002 ◽  
Vol 744 ◽  
Author(s):  
C. Persson ◽  
R. Ahuja ◽  
J. Souza de Almeida ◽  
B. Johansson ◽  
C. Y. An ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Band Gap Energy ◽  
Full Potential ◽  
Generalized Gradient ◽  
Calculated Density ◽  
Augmented Plane Wave ◽  
Gap Energy ◽  
Generalized Gradient Approximation ◽  
Absorption Measurements

ABSTRACTThe optical properties of SbBiI3 alloys have been investigated experimentally by absorption measurements and theoretically by a full-potential augmented plane wave (FPLAPW) method within the generalized gradient approximation. The fundamental band-gap energy of these alloys changes from BiI3- to SbI3-like with increasing percentage of Sb content. The calculated band-gap energies as well as the optical absorption were found to be in a very good qualitatively agreement with the experimental results. We present calculated density-of-states as well as the dielectric functions for evaluation of future experiments.

Determination of stress of DLC films from below band gap optical absorption measurements

Vacuum ◽  
1996 ◽  
Vol 47 (3) ◽  
pp. 233-238 ◽  
Author(s):  
M Basu ◽  
J Dutta ◽  
S Chaudhuri ◽  
AK Pal ◽  
M Nakayama
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Absorption Measurements

ELECTRICAL RESISTIVITY, HALL COEFFICIENT, AND THERMOELECTRIC POWER OF AuSb2 AND Cu2Sb

1964 ◽  
Vol 42 (3) ◽  
pp. 519-525 ◽  
Author(s):  
W. B. Pearson
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Thermoelectric Power ◽  
Hall Coefficient ◽  
Low Temperatures ◽  
Room Temperature ◽  
Iron Impurity

The electrical conductivity and absolute thermoelectric power of AuSb2 and Cu2Sb have been measured between 2.5° and 300 °K. Room-temperature Hall coefficients were also determined. Iron impurity causes a giant diffusion thermoelectric power at low temperatures in the compound Cu2Sb, as it has previously been found to do in Cu, Ag, and Au.

Role of Metal Phthalocyanine in Redox Complex Conductivity of Polyaniline and Aniline Black

1999 ◽  
Vol 03 (07) ◽  
pp. 679-686 ◽  
Author(s):  
FRANCIS P. XAVIER ◽  
ANTO REGIS INIGO ◽  
GEORGE J. GOLDSMITH
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Optical Absorption ◽  
Band Gap ◽  
Copper Phthalocyanine ◽  
Oxidative Polymerization ◽  
Critical Ratio ◽  
Electrical Measurements ◽  
Free Standing

Polyaniline (PA) and aniline black (AB) were prepared in powder form by the chemical method of oxidative polymerization, from which free-standing thin films were obtained by solvent evaporation using N-methyl pyrrolidinone ( NMP ). The thin films contained 2, 4, 6 or 8 wt% AB. Electrical measurements showed that the samples containing 4% AB exhibited the highest photoconductivity of the four concentrations. Thus there appears to be a critical ratio of PA to AB for maximum photoconductivity. Annealing up to 570 K has little effect on the conductivity. Upon adding a small quantity of copper phthalocyanine ( CuPc ) to the PA + AB, the electrical conductivity increased considerably and the optical absorption was extended from the UV to the near IR. The electrical conductivity mechanism is a consequence of a redox process, since AB is the oxidized state of PA and, upon illumination, there is an exchange of charge carriers. The extension of the range of optical absorption upon addition of CuPc is interpreted to suggest that CuPc photosensitizes the material and enhances the carrier transport process in the redox couple. The activation energy from the temperature-dependent conductivity and the band gap from the electrolyte electroreflectance method were determined. The activation energy for 0.4% CuPc is lowest (0.52 eV) and the corresponding band gap is determined to be 3.0 eV. This organic compound could be a good candidate for inexpensive, reliable and efficient solar energy-converting devices.

Temperature Dependence of the Electrical Conductivity of Poly(Benzo[1,2-b:4,5-b'] Dithiophene-4,8-Diyl Vinylene) and Poly(Dodecylthiophene)

1997 ◽  
Vol 488 ◽  
Author(s):  
R. C Hyer ◽  
R. G. Pethe ◽  
T. Yogi ◽  
S. C. Sharma ◽  
J. Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
Room Temperature ◽  
Thermal Fluctuation ◽  
Variable Range Hopping ◽  
Tunneling Model ◽  
Three Samples ◽  
Electrical Conductivities

AbstractWe present results for the electrical conductivity (σ) of thin films of poly(benzo[1,2-b:4,5- b']dithiophene-4,8-diyl vinylene) (PBDV) and poly (dodecylthiophene) (PDDT) as a function of temperature in the range 15-295K. The polymers were doped with FeC13 and PF6 which resulted in electrical conductivities differing by two orders of magnitude at room temperature. We examine three sets of σ(T)-data by using the variable-range hopping (VRH) model that predicts a linear relationship between ln(T1/2σ) and T1/4. We observe a change in the slope of the ln(T1/2σ) vs T14 relationship in all three samples at low temperatures. We also analyze the temperature dependence of the resistivity of PBDV by using the thermal fluctuation-induced tunneling model.

Pressure coefficient of the direct band gap ofAlxGa1−xAsfrom optical absorption measurements

1979 ◽  
Vol 20 (6) ◽  
pp. 2398-2400 ◽  
Author(s):  
N. Lifshitz ◽  
A. Jayaraman ◽  
R. A. Logan ◽  
R. G. Maines
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Pressure Coefficient ◽  
Direct Band Gap ◽  
Direct Band ◽  
Absorption Measurements

Modulation of the band structures and optical properties of holey C2N nanosheets by alloying with group IV and V elements

2016 ◽  
Vol 4 (39) ◽  
pp. 9294-9302 ◽  
Author(s):  
Juan Du ◽  
Congxin Xia ◽  
Tianxing Wang ◽  
Wenqi Xiong ◽  
Jingbo Li
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Band Gap ◽  
Group Iv ◽  
Band Structures ◽  
Alloy Concentration

The band gap and optical absorption can be tuned effectively by the alloy concentration x in the C2N1−xPx and C2N1−xAsx alloys.

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