Photoluminescence Studies of Impurities and Defects in Mercuric Iodide

1989 ◽  
Vol 163 ◽  
Author(s):  
X.J. Bao ◽  
T.E. Schlesinger ◽  
R.B. James ◽  
A.Y. Cheng ◽  
C. Ortale
Keyword(s):  
Chemical Etching ◽  
Front Surface ◽  
Photoluminescence Spectra ◽  
Mercuric Iodide ◽  
Contact Materials ◽  
Bulk Heating ◽  
Photoluminescence Studies ◽  
Nuclear Detectors ◽  
Processing Steps ◽  
Impurities And Defects

AbstractWe have studied the effects of chemical etching in potassium iodide(KI) aqueous solution, vacuum exposure and bulk heating on the photoluminescence(PL) spectra of mercuric i0dide(HgI2). Different contact materials deposited onto HgI2 were also investigated, such as Pd, Cu, Al, Ni, Sn, In, Ag and Ta. These processing steps and the choice of a suitable electrode material are very important in the manufacturing of high-quality mercuric iodide nuclear detectors. Comparisons are made between the front surface photoluminescence and transmission photoluminescence spectra.

Effects of Contact Materials on the Thermally Stimulated Current Spectra of Mercuric Iodide

1992 ◽  
Vol 242 ◽  
Author(s):  
X. J. Bao ◽  
T. E. Schlesinger ◽  
R. B. James ◽  
A. Y. Cheng ◽  
C. Ortale ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Mercuric Iodide ◽  
Thermally Stimulated Current ◽  
Contact Materials ◽  
Energy Capture ◽  
Thermally Stimulated Current Spectroscopy ◽  
Carrier Traps ◽  
Carrier Trap ◽  
Nuclear Detectors ◽  
Trap Activation

ABSTRACTMercuric iodide (HgI2) single crystals deposited with transparent indium-tin-oxide (ITO), and semitransparent gold and nickel contacts were investigated by thermally stimulated current spectroscopy (TSC). The differences in the TSC spectra from these samples indicate that the defect structure in HgI2 may be modified by the contact material. These defects act as carrier traps and have strong implications in the application of HgI2 nuclear detectors. A method of numerical analysis was developed to extract information such as carrier trap activation energy, capture cross-section, and trap concentration-lifetime product from the TSC measurements.

Evaluation of Electrical Contact Material Stability on Mercuric Iodide

1993 ◽  
Vol 302 ◽  
Author(s):  
A. Y. Cheng
Keyword(s):  
Free Energy ◽  
Room Temperature ◽  
Electrical Contact ◽  
Radiation Detection ◽  
Electrical Contacts ◽  
Contact Material ◽  
Mercuric Iodide ◽  
Energy Data ◽  
Contact Materials ◽  
Temperature Radiation

ABSTRACTMercuric iodide detectors are leading candidates for room-temperature radiation detection applications. The inherently reactive nature of mercuric iodide limits the number of materials suitable for fabrication of electrical contacts. The theoretical stabilities of elemental contact materials on mercuric iodide were evaluated at 25°C. Additionally, the stabilities of transparent conductive compounds, for photodetector applications, were studied. Calculations were based on Gibbs free energy data, estimates and a series of hypothesized reactions with mercuric iodide. Leading candidate materials were identified and compared to experimental results.

Process Monitoring for Fabrication of Mercuric Iodide Room Temperature Radiation Detectors

1993 ◽  
Vol 324 ◽  
Author(s):  
J. M. Van Scyoc ◽  
T. E. Schlesinger ◽  
H. Yao ◽  
R. B. James ◽  
M. Natarajan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Radiation Detectors ◽  
Electrical Contacts ◽  
Careful Study ◽  
Mercuric Iodide ◽  
Optical Functions ◽  
Processing Step ◽  
Material Choice ◽  
Temperature Radiation ◽  
Processing Steps

AbstractIn the fabrication of mercuric iodide room temperature radiation detectors, as in any semiconductor process, the quality of the final device can be very sensitive to the details of the processing steps. Each processing step can either reduce the intrinsic defects and those extrinsic defects introduced by earlier steps, or it can introduce new defects. In mercuric iodide these defects can act as trapping and recombination centers, thereby degrading immediate device performance or leading to long-term reliability problems. With careful study and monitoring of each step, the process can be modified to improve the end product. In this work we used several techniques to study processing steps and their effects. Photoluminescence spectroscopy and photoionization revealed defects introduced during processing. One critical step is the formation of electrical contacts, as both the material choice and deposition method have an impact. Four point probe sheet resistance methods were used to characterize the loss of material from the contact as it reacted with or moved into the bulk semiconductor. Ellipsometry was used to characterize the intrinsic optical functions of the material, and to study the effects of surface aging on these functions. Results from this work provide suggestions for the modification and monitoring of the detector fabrication process.

Low-temperature Photoluminescence Studies of CdTe Thin Films Deposited on CdS/ZnO/Glass Substrates

2013 ◽  
Vol 1538 ◽  
pp. 261-267
Author(s):  
Corneliu Rotaru ◽  
Sergiu Vatavu ◽  
Christoph Merschjann ◽  
Chris Ferekides ◽  
Vladimir Fedorov ◽  
...  
Keyword(s):  
Laser Excitation ◽  
Complex Structure ◽  
Excitation Power ◽  
Photoluminescence Spectra ◽  
Defect Band ◽  
Phonon Replica ◽  
Glass Substrates ◽  
Cdte Thin Films ◽  
Exciton Annihilation ◽  
Photoluminescence Studies

ABSTRACTThe CdTe photoluminescence spectra of CdTe/CdS/ZnO heterojunctions annealed in the presence of CdCl2 have been analyzed in the 4.7-100K temperature range. The analysis has been performed for laser excitation power between 0.01 mW and 30 mW. The analysis showed that the photoluminescence spectrum in the 1.1-1.6 eV region consists of a defect band (1.437 eV) having complex structure and revealing well contoured LO phonon replicas and bound exciton annihilation in the 1.587-1.593 eV region. The band analysis has been carried out by deconvoluting the spectra. It has been shown that the defect band consists of two elementary bands and their phonon replica. An “unusual” temperature dependence of the defect band has been found.

scholarly journals Effect of silicon resistivity on its porosification using metal induced chemical etching: morphology and photoluminescence studies

2015 ◽  
Vol 2 (3) ◽  
pp. 036501 ◽  
Author(s):  
Shailendra K Saxena ◽  
Gayatri Sahu ◽  
Vivek Kumar ◽  
P K Sahoo ◽  
Pankaj R Sagdeo ◽  
...  
Keyword(s):  
Chemical Etching ◽  
Photoluminescence Studies

Bulk Performance of Improved Mercuric Iodide Nuclear Detectors

1978 ◽  
Vol 25 (1) ◽  
pp. 644-648 ◽  
Author(s):  
M. Schieber ◽  
I. Beinglass ◽  
G. Dishon ◽  
A. Holzer ◽  
G. Yaron
Keyword(s):  
Mercuric Iodide ◽  
Nuclear Detectors
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