48 Result(s)
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Article
Impurity ‘Hot Spots’ in MBE HgCdTe/CdZnTe
In this work, impurity ‘hot spot’ macro-defects—high impurity level macro-defect contaminates were examined. ‘Hot spots’ have very high localized concentrations of: K, Mg, Ni, Cr, Mn, Ca, Al, Na, Fe, and Cu. F...
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Article
Dark Currents in a Fully-Depleted LWIR HgCdTe P-on-n Heterojunction: Analytical and Numerical Simulations
In this paper, we use the theory of Evans and Landsberg, which is a generalization of the Shockley–Read–Hall recombination statistics in the space charge region (SCR), to include effects of Auger and radiative...
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Article
HgTe Quantum Dots for Near-, Mid-, and Long-Wavelength IR Devices
Mercury telluride colloidal quantum dots (CQD) hold potential for the fabrication of IR devices that operate in the range of near IR, through short-, mid-, and long wavelength (NIR, SWIR, MWIR, and LWIR, respe...
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Article
Impact of CdZnTe Substrates on MBE HgCdTe Deposition
The highest sensitivity, lowest dark current infrared focal plane arrays (IRFPAs) are produced using HgCdTe on CdZnTe substrates. As-received state-of-the-art CdZnTe 6 × 6 and 7 × 7.5 cm substrates were analyz...
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Article
Analysis of Etched CdZnTe Substrates
State-of-the-art as-received (112)B CdZnTe substrates have been examined for surface impurity contamination and polishing residue. Two 4 cm × 4 cm and one 6 cm × 6 cm (112)B state-of-the-art as-received CdZnTe...
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Article
Band Offsets of III–V and II–VI Materials Studied by Temperature-Dependent Internal Photoemission Spectroscopy
The band offset at the interface of a heterojunction is one of the most important parameters determining the characteristics of devices constructed from heterojunction. Accurate knowledge of band offsets and t...
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Article
Numerical Device Modeling, Analysis, and Optimization of Extended-SWIR HgCdTe Infrared Detectors
Imaging in the extended short-wavelength infrared (eSWIR) spectral band (1.7–3.0 μm) for astronomy applications is an area of significant interest. However, these applications require infrared detectors with extr...
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Article
As-Received CdZnTe Substrate Contamination
State-of-the-art as-received (112)B CdZnTe substrates were examined for surface impurity contamination, polishing damage, and tellurium precipitates/inclusions. A maximum surface impurity concentration of Al =...
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Article
High-Performance MWIR HgCdTe on Si Substrate Focal Plane Array Development
The development of low noise-equivalent differential temperature (NEDT), high-operability midwave infrared (MWIR) focal plane arrays (FPAs) fabricated from molecular beam epitaxial (MBE)-grown HgCdTe on Si-bas...
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Article
Impact of Tellurium Precipitates in CdZnTe Substrates on MBE HgCdTe Deposition
State-of-the-art (112)B CdZnTe substrates were examined for near-surface tellurium precipitate-related defects. The Te precipitate density was observed to be fairly uniform throughout the bulk of the wafer, in...
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Article
Analysis of Mesa Dislocation Gettering in HgCdTe/CdTe/Si(211) by Scanning Transmission Electron Microscopy
Due to its strong infrared absorption and variable band-gap, HgCdTe is the ideal detector material for high-performance infrared focal-plane arrays (IRFPAs). Next-generation IRFPAs will utilize dual-color high...
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Article
Impurity Gettering in (112)B HgCdTe/CdTe/Alternate Substrates
The crystalline structure and impurity profiles of HgCdTe/CdTe/alternate substrate (AS; Si and GaAs are possibilities) and CdTe/AS were analyzed by secondary-ion mass spectrometry, atomic force microscopy, etc...
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Article
Electrooptical Characterization of MWIR InAsSb Detectors
InAs1−x Sb x material with an alloy composition of the absorber layer adjusted to achieve 200-K cutoff wavelengths in the 5-μm range has been grown. Compound-bar...
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Article
Reduction of Dislocation Density by Producing Novel Structures
HgCdTe, because of its narrow band gap and low dark current, is the infrared detector material of choice for several military and commercial applications. CdZnTe is the substrate of choice for HgCdTe as it can...
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Article
Growth and Analysis of HgCdTe on Alternate Substrates
Dislocations generated at the HgCdTe/CdTe(buffer layer) interface are demonstrated to play a significant role in influencing the crystalline characteristics of HgCdTe epilayers on alternate substrates (AS). A ...
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Article
Reduction of Dislocation Density in HgCdTe on Si by Producing Highly Reticulated Structures
HgCdTe, because of its narrow band gap and low dark current, is the infrared detector material of choice for several military and commercial applications. CdZnTe is the substrate of choice for HgCdTe as it can...
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Article
Spectral Response Model of Backside-Illuminated HgCdTe Detectors
Backside-illuminated HgCdTe detectors fabricated on thick CdZnTe substrates have an optical path such that the incident radiation traverses the antireflection (AR) coating layers, the thick CdZnTe substrate, a...
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Article
Dislocation Analysis in (112)B HgCdTe/CdTe/Si
High-quality (112)B HgCdTe/Si epitaxial films with a dislocation density of ∼9 × 105 cm−2 as determined by etch pit density (EPD) measurements have been obtained by thermal cyclic annealing (TCA). The reduction o...
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Article
The Distribution Tail of LWIR HgCdTe-on-Si FPAs: a Hypothetical Physical Mechanism
A model is proposed to explain disparities found in the operability values and histograms for long-wavelength infrared HgCdTe focal-plane arrays fabricated on Si substrates compared with those fabricated on Cd...
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Article
Characterization of Dislocations in (112)B HgCdTe/CdTe/Si
The electrical performance of HgCdTe/Si photodiodes is shown not to have a direct relationship with the dislocation density as revealed by defect etching. This has led to an equivalent circuit model to explain...
