Below band-gap optical absorption and photoluminescence excitation spectroscopy at room temperature in low-defect-density bulk GaN:Fe

2012 ◽  
Vol 100 (3) ◽  
pp. 031908 ◽  
Author(s):  
P. Gladkov ◽  
E. Hulicius ◽  
T. Paskova ◽  
E. Preble ◽  
K. R. Evans
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Room Temperature ◽  
Defect Density ◽  
Photoluminescence Excitation

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.

Artificial Atoms of Silicon

1999 ◽  
Vol 582 ◽  
Author(s):  
Justin D. Holmes ◽  
Kirk J. Ziegler ◽  
Keith P. Johnston ◽  
R. Chris Doty ◽  
Brian A. Korgel
Keyword(s):  
Quantum Yield ◽  
Band Gap ◽  
Silicon Nanocrystals ◽  
Room Temperature ◽  
Band Edge ◽  
Electronic Transitions ◽  
Photoluminescence Excitation ◽  
Blue Band ◽  
Artificial Atoms ◽  
Indirect Band Gap

ABSTRACTSize-monodisperse, stable 15 Å diameter silicon nanocrystals were synthesized in significant quantities using supercritical octanol as a capping ligand. The silicon nanocrystals exhibit an indirect band gap with discrete electronic transitions in the absorbance and photoluminescence excitation (PLE) spectra. The octanol-capped clusters show efficient blue band-edge photoemission with a luminescence quantum yield of 23 % at room temperature.

Photoluminescence excitation by band‐gap optical absorption in chemical vapor deposition diamond films

1991 ◽  
Vol 69 (6) ◽  
pp. 3702-3708 ◽  
Author(s):  
Lawrence H. Robins ◽  
Paul J. H. Tjossem ◽  
Kermit C. Smyth ◽  
P. Yvonne Barnes ◽  
Edward N. Farabaugh ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Optical Absorption ◽  
Band Gap ◽  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Diamond ◽  
Photoluminescence Excitation

Absorption and photoluminescence studies of lightly alloyed CdTe(S) and CdS(Te)

2001 ◽  
Vol 668 ◽  
Author(s):  
Diana Shvydka ◽  
A.D. Compaan ◽  
K.J. Price
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
Room Temperature ◽  
Rf Sputtering ◽  
Near Band Edge ◽  
Photoluminescence Excitation ◽  
Defect States ◽  
Rich Alloy ◽  
Photoluminescence Studies ◽  
Gap States

ABSTRACTCdTe-rich and CdS-rich alloy films were deposited at temperatures less than 300C using an rf sputtering technique. Transmission-reflection and photoluminescence measurements were conducted to study the near-band edge properties of this ternary system for films of different compositions at room temperature and at 10K. Results were compared to data on defect states introduced in CdTe single crystal by annealing at several different overpressure conditions, including CdS and CdCl2 overpressures. A below-band-gap photoluminescence excitation technique was used to study systematically the effect of different steps in the production of the complete solar cell on band gap states of CdSxTe1−x alloys as well as pure binary constituents.

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.

Optical absorption and band gap shift of n-doped Al Ga1−As alloys grown by MBE

1998 ◽  
Vol 43-44 ◽  
pp. 423-429 ◽  
Author(s):  
A. Ferreira da Silva ◽  
C. Persson ◽  
K.-F. Berggren ◽  
I. Pepe ◽  
A. Santos Alves ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap

Electronic structure engineering of tin telluride through co-doping of bismuth and indium for high performance thermoelectrics: a synergistic effect leading to a record high room temperature ZT in tin telluride

2019 ◽  
Vol 7 (16) ◽  
pp. 4817-4821 ◽  
Author(s):  
U. Sandhya Shenoy ◽  
D. Krishna Bhat
Keyword(s):  
Electronic Structure ◽  
Synergistic Effect ◽  
Band Gap ◽  
High Performance ◽  
Room Temperature ◽  
Band Offset ◽  
Valence Band Offset ◽  
Co Doping ◽  
Tin Telluride ◽  
Structure Engineering

Resonance states due to Bi and In co-doping, band gap enlargement, and a reduced valence-band offset in SnTe lead to a record high room-temperature ZT.

scholarly journals Gold-Hyperdoped Germanium with Room-Temperature Sub-Band-Gap Optoelectronic Response

2020 ◽  
Vol 14 (6) ◽  
Author(s):  
Hemi H. Gandhi ◽  
David Pastor ◽  
Tuan T. Tran ◽  
S. Kalchmair ◽  
L.A. Smilie ◽  
...  
Keyword(s):  
Band Gap ◽  
Room Temperature

Energy Band Gap Studies of CdS Nanomaterials

2008 ◽  
Vol 3 ◽  
pp. 97-102 ◽  
Author(s):  
Dinu Patidar ◽  
K.S. Rathore ◽  
N.S. Saxena ◽  
Kananbala Sharma ◽  
T.P. Sharma
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Energy Band ◽  
Chemical Method ◽  
Optical Absorption Spectroscopy ◽  
Cds Nanoparticles ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Simple Chemical

The CdS nanoparticles of different sizes are synthesized by a simple chemical method. Here, CdS nanoparticles are grown through the reaction of solution of different concentration of CdCl2 with H2S. X-ray diffraction pattern confirms nano nature of CdS and has been used to determine the size of particle. Optical absorption spectroscopy is used to measure the energy band gap of these nanomaterials by using Tauc relation. Energy band gap ranging between 3.12 eV to 2.47 eV have been obtained for the samples containing the nanoparticles in the range of 2.3 to 6.0 nm size. A correlation between the band gap and size of the nanoparticles is also established.

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