Identification and characterization of traps in ingaas short wavelength infrared photodetectors by deep level transient spectroscopy

Download
2016
Avishan, Nardin
Unintentionally added impurities during the epitaxial growth and lattice defects may cause deep level traps in the bandgap of semiconductors. They can strongly affect the electrical and optical properties of semiconductors. Studying these energy levels and providing feedback to the material growth and device fabrication processes are important in order to identify the performance limiting mechanisms and optimize the characteristics of semiconductor devices. Deep Level Transient Spectroscopy (DLTS) technique is commonly used for this purpose. In this thesis, the electrical properties of traps in molecular beam epitaxy (MBE) grown InxGa1-xAs with In mole fractions (x) of 0.53 and 0.83 are identified and characterized. The epilayers were grown on InP substrate. One electron trap at Ec−0.33 eV and one hole trap at Ev+0.15 eV were detected in the lattice-matched In0.53Ga0.47As/InP p-i-n photodiodes with different absorber doping densities. Two hole traps with energy levels of Ev+0.10 eV and Ev+0.31 eV were detected in the lattice-mismatched In0.83Al0.17As/In0.83Ga0.17As/InP heterojunction p-i-n photodetector grown with a linearly graded InxAl1-xAs buffer layer. The results were compared with the trap characteristics reflected by the G-R component of the dark current in the photodetectors fabricated with the epilayer structure and good agreement was obtained. The dominant trap degrading the detector characteristics was found to display extended defect characteristic with a capture cross section of 5.3x10-16 cm2, density of 1.8x1015 cm-3 and activation energy of 0.31 eV.

Suggestions

Design and implementation of high fill factor structures on low-cost uncooled infrared sensors
Ertürk, Ozan; Akın, Tayfun; Department of Electrical and Electronics Engineering (2015)
This thesis presents the design and implementation steps of high fill factor structures for existing SOI diode low-cost microbolometer FPAs. Advancements in uncooled infrared detectors enable high performance military grade uncooled microbolometers as well as ultra-low-cost infrared imagers for civilian applications. The trend in uncooled microbolometers to reduce the pixel pitch has become increasingly significant to lower the cost of detector and system integration due to optics, and increase spatial reso...
Investigation of thermal degradation characteristics of polyamide-6 containing melamine or melamine cyanurate via direct pyrolysis mass spectrometry
Isbasar, Ceyda; Hacaloğlu, Jale (2012-01-01)
In this work the changes in thermal degradation characteristics of polyamide 6 (PA6) in the presence of melamine (Me) or melamine cyanurate (MC) were investigated systematically via direct pyrolysis mass spectrometry. Though thermal stability of PA6 was not affected by the presence of flame retardants, the changes in the products and in their distributions were detected. The reaction of carbonyl groups of PA6 with amine groups of melamine was the main cause for the changes in the product distribution. In th...
Effect of swaging on microstructure and tensile properties of W-Ni-Fe alloys
DURLU, NURİ; Caliskan, N. Kaan; Bor, Sakir (Elsevier BV, 2014-01-01)
The objective of this study was to investigate the effect of swaging on the microstructure and tensile properties of high density two phase alloys 90W-7Ni-3Fe and 93W-4.9Ni-2.1Fe. Samples were liquid phase sintered under hydrogen and argon at 1480 degrees C for 30 min and then 15% cold rotary swaged. Measurement of microstructural parameters in the sintered and swaged samples showed that swaging slightly increased tungsten grain size in the longitudinal direction and slightly decreased tungsten grain size i...
Characterization of Duplex Stainless Steel Weld Metals Obtained by Hybrid Plasma-Gas Metal Arc Welding
Yurtışık, Koray; Tirkeş, Süha; Gür, Cemil Hakan; Gürbüz, Rıza (FapUNIFESP (SciELO), 2013-07-01)
Despite its high efficiency, autogenous keyhole welding is not well-accepted for duplex stainless steels because it causes excessive ferrite in as-welded duplex microstructure, which leads to a degradation in toughness and corrosion properties of the material. Combining the deep penetration characteristics of plasma arc welding in keyhole mode and metal deposition capability of gas metal arc welding, hybrid plasma - gas metal arc welding process has considered for providing a proper duplex microstructure wi...
Molecular dynamics study of random and ordered metals and metal alloys
Kart, Hasan Hüseyin; Tomak, Mehmet; Department of Physics (2004)
The solid, liquid, and solidification properties of Pd, Ag pure metals and especially PdxAg1-x alloys are studied by using the molecular dynamics simulation. The effects of temperature and concentration on the physical properties of PdxÞAg1-x are analyzed. Sutton-Chen (SC) and Quantum Sutton-Chen (Q-SC) many-body potentials are used as interatomic interactions which enable one to investigate the thermodynamic, static, and dynamical properties of transition metals. The simulation results such as cohesive ene...
Citation Formats
N. Avishan, “Identification and characterization of traps in ingaas short wavelength infrared photodetectors by deep level transient spectroscopy,” M.S. - Master of Science, Middle East Technical University, 2016.