Mapping of Defects in Metal-Semiconductor-Metal (MSM) Detectors in Hg1−xCdxTe by Nuclear Microprobe

1993 ◽  
Vol 302 ◽  
Author(s):  
Patrick W. Leech ◽  
Sean P. Dooley ◽  
David N. Jamieson
Keyword(s):  
Active Region ◽  
Dark Current ◽  
Linear Growth ◽  
Cdte Layer ◽  
Nuclear Microprobe ◽  
High Quality ◽  
Growth Defects ◽  
Metal Semiconductor Metal ◽  
Contrast Microscopy ◽  
Equivalent Conditions

ABSTRACTThe incidence of compositional and structural inhomogenieties in MSM detectors based on Hg1−xCdxTe/GaAs and Hg1−xCdxTe/GaAs/Si has been examined by nuclear microprobe. With a 2 MeV He+ beam focussed to ≥5 μm, the microprobe has demonstrated the capability for RBS channelling in the active region of a Hg1−xCdxTe device and the imaging of defects by Channelling Contrast Microscopy (CCM). A series of linear growth defects in some Hg1−xCdxTe devices were identified using CCM. The channelling RBS spectra from these regions have shown an increase in χmin compared with the surrounding high quality crystal. The occurence of these defects was associated with a degradation in the performance of affected devices in an array. RBS spectra have also revealed the presence of an anomalous CdTe layer, correlating with a significant reduction in dark current and increase in breakdown voltage of these devices. RBS channelling of individual devices has identified differences in χmin between arrays which were prepared under equivalent conditions of growth and processing.

Mapping of Defects in Metal-Semiconductor-Metal (MSM) Detectors in Hg1−xCdxTe by Nuclear Microprobe

1994 ◽  
Vol 299 ◽  
Author(s):  
Patrick W. Leech ◽  
Sean P. Dooley ◽  
David N. Jamieson
Keyword(s):  
Active Region ◽  
Dark Current ◽  
Linear Growth ◽  
Cdte Layer ◽  
Nuclear Microprobe ◽  
High Quality ◽  
Growth Defects ◽  
Metal Semiconductor Metal ◽  
Contrast Microscopy ◽  
Equivalent Conditions

AbstractThe incidence of compositional and structural inhomogenieties in MSM detectors based on Hg1−xCdxTe/GaAs and Hg1−xCdxTe/GaAs/Si has been examined by nuclear microprobe. With a 2 MeV He+ beam focussed to ≤5 μm, the microprobe has demonstrated the capability for RBS channelling in the active region of a Hg1−xCdxTe device and the imaging of defects by Channelling Contrast Microscopy (CCM). A series of linear growth defects in some Hg1−xCdxTe devices were identified using CCM. The channelling RBS spectra from these regions have shown an increase in χmin compared with the surrounding high quality crystal. The occurence of these defects was associated with a degradation in the performance of affected devices in an array. RBS spectra have also revealed the presence of an anomalous CdTe layer, correlating with a significant reduction in dark current and increase in breakdown voltage of these devices. RBS channelling of individual devices has identified differences in χmin between arrays which were prepared under equivalent conditions of growth and processing.

High-Irradiance Degradation Studies of Metamorphic 1eV GaInAs Solar Cells

2012 ◽  
Vol 1432 ◽  
Author(s):  
Ryan M. France ◽  
Myles A. Steiner
Keyword(s):  
Solar Cells ◽  
Active Region ◽  
Dislocation Density ◽  
Dark Current ◽  
Degradation Mechanism ◽  
Control Cell ◽  
High Irradiance ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Degradation Studies

ABSTRACTInitial tests are performed regarding the degradation of lattice-mismatched GaInAs solar cells. 1eV metamorphic GaInAs solar cells with 1-2×106 cm-2 threading dislocation density in the active region are irradiated with an 808 nm laser for 2 weeks time under a variety of temperature and illumination conditions. All devices show a small degradation in Voc that is logarithmic with time. The absolute loss in performance after 2 weeks illuminated at 1300 suns equivalent and 125°C is 7 mV Voc and 0.2% efficiency, showing these devices to be relatively stable. The dark current increases with time and is analyzed with a two-diode model. A GaAs control cell degrades at the same rate, suggesting that the observed degradation mechanism is not related to the additional dislocations in the GaInAs devices.

scholarly journals Suppression of dark current in GeO_x-passivated germanium metal-semiconductor-metal photodetector by plasma post-oxidation

2015 ◽  
Vol 23 (13) ◽  
pp. 16967 ◽  
Author(s):  
Jian Kang ◽  
Rui Zhang ◽  
Mitsuru Takenaka ◽  
Shinichi Takagi
Keyword(s):  
Dark Current ◽  
Metal Semiconductor Metal

THE STUDY OF Pd SCHOTTKY CONTACT ON POROUS GaN FOR UV METAL–SEMICONDUCTOR–METAL (MSM) PHOTODETECTORS

2007 ◽  
Vol 16 (04) ◽  
pp. 497-503 ◽  
Author(s):  
L. S. CHUAH ◽  
Z. HASSAN ◽  
H. ABU HASSAN
Keyword(s):  
Molecular Beam Epitaxy ◽  
Tensile Stress ◽  
Molecular Beam ◽  
Schottky Contact ◽  
Nitrogen Plasma ◽  
Porous Sample ◽  
Optical Studies ◽  
High Quality ◽  
Metal Semiconductor Metal ◽  
Msm Photodetectors

High quality unintentionally doped n-type GaN layers were grown on Si (111) substrate using AlN (about 200 nm) as buffer layer by radio frequency (RF) nitrogen plasma-assisted molecular beam epitaxy (MBE). This paper presents the structural and optical studies of porous GaN sample compared to the corresponding as-grown GaN. Metal–semiconductor–metal (MSM) photodiode was fabricated on the samples. For as-grown GaN-based MSM, the detector shows a sharp cut-off wavelength at 362 nm, with a maximum responsivity of 0.254 A/W achieved at 360 nm. For porous GaN MSM detector, a sharp cut-off wavelength at 360 nm with a maximum responsivity of 0.655 A/W was achieved at 359 nm. Both the detectors show a little decrease in responsivity in the UV spectral region. The MSM photodiode based on porous GaN shows enhanced (2×) magnitude of responsivity relative to the as-grown GaN MSM photodiode. Enhancement of responsivity can be attributed to the relaxation of tensile stress and reduction of surface pit density in the porous sample.

scholarly journals Additive Modulated Perovskite Microstructures for High Performance Photodetectors

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1090
Author(s):  
Zhan Gao ◽  
Yifan Zheng ◽  
Guancheng Huang ◽  
Genjie Yang ◽  
Xinge Yu ◽  
...  
Keyword(s):  
Molecular Interactions ◽  
Dark Current ◽  
High Performance ◽  
Visible Region ◽  
Carbonyl Groups ◽  
High Quality ◽  
Inorganic Hybrid ◽  
Simple Route ◽  
High Efficient ◽  
Crystallographic Defects

Organic-inorganic hybrid perovskites have been widely used as light sensitive components for high-efficient photodetectors due to their superior optoelectronic properties. However, the unwanted crystallographic defects of perovskites typically result in high dark current, and thus limit the performance of the device. Herein, we introduce a simple route of microstructures control in MAPbI3 perovskites that associates with introducing an additive of 3,3,4,4-benzophenonetetracarboxylic dianhydridean (BPTCD) for crystallization adjustment of the perovskite film. The BPTCD additive can facilitate the formation of high-quality perovskite film with a compact and nearly pinhole-free morphology. Through characterizing the molecular interactions, it was found that the carbonyl groups in BPTCD is the key reason that promoted the nucleation and crystallization of MAPbI3. As a result, we obtained high-efficient and stable perovskite photodetectors with low dark current of 9.98 × 10−8 A at −0.5 V, an on/off ratio value of 103, and a high detectivity exceeding 1012 Jones over the visible region.

Analysis of screw dislocation mediated dark current in Al0.50Ga0.50N solar-blind metal-semiconductor-metal photodetectors

2018 ◽  
Vol 498 ◽  
pp. 35-42 ◽  
Author(s):  
Shashwat Rathkanthiwar ◽  
Anisha Kalra ◽  
Rangarajan Muralidharan ◽  
Digbijoy N. Nath ◽  
Srinivasan Raghavan
Keyword(s):  
Screw Dislocation ◽  
Dark Current ◽  
Metal Semiconductor Metal ◽  
Solar Blind

Analysis of Faceted Growth Hillocks in MOCVD Grown Epitaxial HgCdTe on GaAs with a Nuclear Microprobe

1991 ◽  
Vol 238 ◽  
Author(s):  
David N. Jamieson ◽  
S. P. Dooley ◽  
S. P. Russo ◽  
P. N. Johnston ◽  
G. N. Pain ◽  
...  
Keyword(s):  
Chemical Vapour ◽  
Normal Growth ◽  
Areal Density ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Epitaxial Layers ◽  
Nuclear Microprobe ◽  
Growth Defects ◽  
Gaas Substrates ◽  
Metal Organic

ABSTRACTHg1-xCdxTe epitaxial layers on GaAs substrates grown by Metal Organic Chemical Vapour Deposition (MOCVD) display growth defects resembling pyramidal faceted hillocks which appear to originate from defects originally present on the substrate. For <100> oriented GaAs substrates and normal growth conditions, these growth defects have an areal density of 1–1000 mm-2. The size of the hillocks depends on the layer thickness and they have the potential to degrade performance of optoelectronic devices fabricated in the epitaxial layers. Nuclear microprobe analysis, performed with a 2 MeV He+ beam focused to less than 5 μm in diameter, has allowed the hillocks to be imaged with the technique of Channeling Contrast Microscopy (CCM). Channeling spectra, obtained by Rutherford Backseat tering Spectrometry (RBS) of the hillocks themselves, showed that the χmin was 13 %. This was similar to the χmin of the high quality single crystal surrounding material. The CCM images also revealed extensive regions of poor channeling, with shapes that suggested that the regions originally arose from scratches in the substrate. These poor channeling regions were not readily observable by other techniques.

Surface Passivation and the Ultrafast Optical Response of Low-Temperature-Grown GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
H. H. Wang ◽  
J. F. Whitaker ◽  
K. Al-Hemyari ◽  
S. L. Williamson
Keyword(s):  
Low Temperature ◽  
Dark Current ◽  
Surface Passivation ◽  
Surface States ◽  
Time Response ◽  
Temporal Response ◽  
Dc Voltage ◽  
Ultrafast Optical ◽  
Metal Semiconductor Metal ◽  
Low Temperature Grown Gaas

AbstractMetal-semiconductor-metal photodetectors fabricated using low-temperature-grown GaAs have been passivated using AlGaAs cap layers in order to understand the influence of surface states and fields on the properties of these detectors. It has been found that passivation has little effect on the time response or persistent photoconductive tails associated with the detectors, but that responsivity and dark current can be enhanced in certain circumstances. The dependence of the temporal response on optical fluence and dc-voltage bias were observed for both passivated and unpassivated detectors.

AlInAs/GaInAs metal-semiconductor-metal photodiodes with very low dark current

1991 ◽  
Vol 15 (1-4) ◽  
pp. 267-270 ◽  
Author(s):  
A Temmar ◽  
J.P. Praseuth ◽  
J.F. Palmier ◽  
A. Scavennec
Keyword(s):  
Dark Current ◽  
Metal Semiconductor Metal

Germanium Photodetectors for Silicon Microphotonics by Direct Epitaxy on Silicon

1999 ◽  
Vol 607 ◽  
Author(s):  
Hsin-Chiao Luan ◽  
Desmond R. Lim ◽  
Lorenzo Colace ◽  
Gianlorezo Masini ◽  
Gaetano Assanto ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Thermal Annealing ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Annealing Process ◽  
Threading Dislocation ◽  
High Quality ◽  
Cyclic Annealing ◽  
Metal Semiconductor Metal ◽  
Dislocation Densities

AbstractWe have grown high-quality Ge epilayers on Si using two-step ultrahigh vacuum/chemical-vapor-deposition followed by post-growth cyclic thermal annealing. Cyclic annealing was effective in reducing threading dislocation densities. The annealing process was improved by optimizing the dislocation velocity. We fabricated and tested metal-semiconductor-metal planar photodetectors using Ge epilayers grown on Si. Our measurement showed an improvement in the photodetector performance as a result of the improved materials quality. The process described in this paper for making high-quality Ge on Si is uncomplicated and can be easily integrated with Si CMOS processes.

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