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Two Color Photodetector Using An Asymmetric Quantum Well Structure
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Book Synopsis Two-Color Photodetector Using an Asymmetric Quantum Well Structure by : Kevin R. Lantz
Download or read book Two-Color Photodetector Using an Asymmetric Quantum Well Structure written by Kevin R. Lantz and published by . This book was released on 2002-06 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past twenty years have seen an explosion in the realm of infrared detection technology fueled by improvements in III-V semiconductor technology and by new semiconductor growth methods. One of the fastest growing areas of this research involves the use of bandgap engineering in order to create artificial quantum wells for use in Quantum Well Infrared Photodetectors (QWIPs) . QWIPs have an advantage over other infrared detectors such as Mercury Cadmium Telluride (MCT) because they have larger bandgaps and are therefore stronger and cheaper to manufacture. This thesis introduces one method of multi-color' detection through the use of an asymmetries quantum well structure in which all energy transitions are possible. The QWIP structure in this thesis was designed to detect a laser wavelength of 1.06 micrometers and a wavelength in the 8-10 micrometers atmosphere window. The relevance of a detector that is tuned to these wavelengths is that it can be used on military aircraft as a laser spot tracker and an infrared imager providing much greater accuracy and dependability than older systems.
Book Synopsis Design of a Voltage Tunable Broadband Quantum Well Infrared Photodetector by : Atakan Konukbay
Download or read book Design of a Voltage Tunable Broadband Quantum Well Infrared Photodetector written by Atakan Konukbay and published by . This book was released on 2002-06 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this thesis is to design a quantum well infrared detector with tunable spectral bandwidth. The tunability of the bandwidth is achieved by using the linear Stark effect for the ground to first excited state transition in an asymmetric quantum well. The position of the absorption peak is dependent on the direction of the electric field, and therefore it can be either blue or red shifted by changing the direction of the field. If two identical asymmetric quantum wells are arranged opposite each other, we can obtain both the blue and red shift for either direction of the bias. This method can produce broader peaks with tunable bandwidths proportional to the applied field. A program was developed to calculate the energy levels and wavefunctions of an arbitrary quantum well. The program was used to design a step quantum well capable of detecting infrared in the 8-12 micrometers band. The validity of the approach was verified by comparison with experimental data and found to have a good agreement. The designed step well was used to create a tunable bandwidth detector. The analysis showed that the bandwidth could be tuned to more than twice the peak width. The numerical simulation indicates the possibility of manufacturing a tunable bandwidth infrared detector by using step quantum wells.
Book Synopsis Intersubband Transitions in Quantum Wells: Physics and Device Applications by :
Download or read book Intersubband Transitions in Quantum Wells: Physics and Device Applications written by and published by Academic Press. This book was released on 1999-10-28 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The Willardson and Beer series, as it is widely known, has succeeded in producing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise that this tradition will be maintained and even expanded. Reflecting the truly interdisciplinary nature of the field that the series covers, the volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in modern industry.
Book Synopsis Intersubband Transitions in Quantum Wells: Physics and Devices by : Sheng S. Li
Download or read book Intersubband Transitions in Quantum Wells: Physics and Devices written by Sheng S. Li and published by Springer. This book was released on 1998-07-31 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of Intersubband Transitions in Quantum Wells: Physics and Devices is to facilitate the presentation and discussion of the recent results in theoretical, experimental, and applied aspects of intersubband transitions in quantum wells and dots. This reference work is based on the International Workshop that was held at National Cheng Kung University in Tainan, Taiwan in December 15-18, 1997. Intersubband transitions in quantum wells and quantum dots have attracted considerable attention in recent years, mainly due to the promise of various applications in the mid- and far-infrared regions (2-30 mum). Over 40 invited and contributed papers were presented in this four-day workshop, with topics covering most aspects of the intersubband transition phenomena including: the basic intersubband transition process, multiquantum well infrared photodetector (QWIP) physics, large format (640×480) GaAs QWIP (with 9.0 mum cutoff) focal plane arrays (FPAs) for IR imaging camera applications, infrared modulation, intersubband emission including mid- and long-wavelength quantum cascade (QC) lasers such as short (lambda = 3.4 mum) and long (lambda = 11.5 mum) wavelength room temperature QC lasers, quantum fountain intersubband laser at 15.5 mum wavelength in GaAs/AIGaAs quantum well, harmonic generation and nonlinear effects, ultra-fast phenomena such as terahertz (THz) intersubband emission and detection. Intersubband Transitions in Quantum Wells: Physics and Devices will be of interest to researchers from universities and industrial laboratories working on physics and devices of nanostructures, and researchers in the infrared (IR) community.
Book Synopsis Optoelectronics, Materials, and Devices for Communications by : Tien-Pei Lee
Download or read book Optoelectronics, Materials, and Devices for Communications written by Tien-Pei Lee and published by SPIE-International Society for Optical Engineering. This book was released on 2001 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Nonlinear Quantum Well Photodetectors Using Frequency Up Conversion by : Venkata Ramalaxmi Chaganti
Download or read book Nonlinear Quantum Well Photodetectors Using Frequency Up Conversion written by Venkata Ramalaxmi Chaganti and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I describe mid/far-infrared photodetectors based on frequency upconversion in a near-resonant cascade of interband and intersubband transitions in high optical non-linearity asymmetric quantum well structures. Such structures can yield high detectivity and responsivity in the mid/far-infrared range. Resonant uponversion detectors can be designed for both collinear and perpendicular pump and signal beams. They can be integrated with semiconductor pump lasers to yield compact devices. Single photon counting is also achieved by these detectors. I present specific device designs based on GaAs/AlGaAs and InGaAs/AlInAs heterostructures and calculations of their expected figures of merit. This includes a study of the intersubband nonlinear absorption of asymmetric double quantum wells designed for mid/far-IR range. The dependance of second order nonlinear susceptibility on various parameters of the structure is studied. In particular, different values for barrier and well widths are considered. The nonlinear absorption can be obtained by using perturbative calculation of the linear susceptibility up to second order with density matrix approach. The intersubband linear and nonlinear asymmetric double quantum well can be tuned using two design parameters. One is the width of the barrier between the wells that controls the coupling and the second is the width of the narrow well that controls the asymmetry of the structure. As the barrier width narrows the energy gap at the anticrossing increases. The asymmetry of the two well potentials is essential for sum frequency and difference frequency generation since in a symmetric well Z31 = 0 due to the same parity of the ground and second excited states so that x(2) = 0. In our detection scheme using frequency up-conversion we demonstrate that these devices can achieve high detectivity, very low noise and high value for x(2) hence good efficiency. This can be an important advantage for low signal detection and single photon counting.
Book Synopsis Introduction to Optical and Optoelectronic Properties of Nanostructures by : Vladimir V. Mitin
Download or read book Introduction to Optical and Optoelectronic Properties of Nanostructures written by Vladimir V. Mitin and published by Cambridge University Press. This book was released on 2019-03-21 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rigorous guide providing a unified, multidisciplinary treatment of the fundamentals of optical and optoelectronic nanostructures.
Book Synopsis Proceedings of the Second International Conference on Long Wavelength Infrared Dectectors and Arrays, Physics and Applications by : V. Swaminathan
Download or read book Proceedings of the Second International Conference on Long Wavelength Infrared Dectectors and Arrays, Physics and Applications written by V. Swaminathan and published by The Electrochemical Society. This book was released on 1995 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Proceedings of IEEE Sensors ... by :
Download or read book Proceedings of IEEE Sensors ... written by and published by . This book was released on 2002 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Multi-Color Quantum Well Infrared Photodetectors for Mid-, Long-, and Very Long- Wavelength Infrared Applications by : Sheng S. Li
Download or read book Multi-Color Quantum Well Infrared Photodetectors for Mid-, Long-, and Very Long- Wavelength Infrared Applications written by Sheng S. Li and published by . This book was released on 2002 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum well infrared photodetectors (QWIPs) have been widely investigated for the 3 - 5 micrometers mid-wavelength infrared (MWIR) and 8 - 12 micrometers long-wavelength infrared (LWIR) atmospheric spectral windows as well as very long wavelength infrared (VLWIR: lambda(sub c)> 14 micrometers) detection in the past decade. The mature III-V compound semiconductor growth technology and the design flexibility of device structures have led to the rapid development of various QWIP structures for infrared focal plane arrays (FPAs) applications. In addition to the single-color QWIP with narrow bandwidth, the multi-color QWIP required for advanced IR sensing and imaging applications have also been emerged in recent years. Using band gap engineering approach, the multi-color (2, 3, and 4- color) QWIPs using multi-stack quantum wells with different well width and depth and voltage-tunable triple-coupled quantum well (TCQW) structure for detection in the MWIR, LWIR, and VLWIR bands have been demonstrated. In this paper, the design, fabrication, and characterization of a voltage-tunable 2-stack 3-color QWIP for MW/LW/LW IR detection and a 3-stack 3-color QWIP for detection in the water, ozone, and CO2 atmospheric blocking bands are depicted.
Book Synopsis Semiconductor Optoelectronic Device Manufacturing and Applications by : David Chen
Download or read book Semiconductor Optoelectronic Device Manufacturing and Applications written by David Chen and published by SPIE-International Society for Optical Engineering. This book was released on 2001 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Combinatorial Materials Synthesis by : Xiao-Dong Xiang
Download or read book Combinatorial Materials Synthesis written by Xiao-Dong Xiang and published by CRC Press. This book was released on 2003-08-19 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pioneered by the pharmaceutical industry and adapted for the purposes of materials science and engineering, the combinatorial method is now widely considered a watershed in the accelerated discovery, development, and optimization of new materials. Combinatorial Materials Synthesis reveals the gears behind combinatorial materials chemistry and thin-
Book Synopsis Investigation of Multicolor and Simplified Quantum Well Infrared Photodetectors for MWIR and LWIR Detection by :
Download or read book Investigation of Multicolor and Simplified Quantum Well Infrared Photodetectors for MWIR and LWIR Detection written by and published by . This book was released on 2000 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research program, we have investigated a four-stack, four-color quantum well infrared photodetector (QWIP), and studied the voltage distribution and temperature effect in this four-color QWIP. We have conducted a study on the quantum confined Stark-effect in an n-type QWIP. We have performed theoretical studies of the intersubband optical transitions in quantum dots and the design of GaAs/InGaAs and InAs/InAlAs quantum dot infrared photodetectors (QDIPs) for MWIR and LWIR detection. A new QWIP for very long wavelength infrared (VLWIR) applications has been investigated for 14-16 (micrometer) detection. Specific issues concerning device physics, detector design and device performance of the VLWIR QWIP are addressed. A VLWIR QWIP has been designed, fabricated and characterized. Two high performance multi-color, broadband QWIPs using digital graded superlattice barriers (DGSLB) for long wavelength infrared (LWIR) and broadband (BB) infrared detection have been demonstrated. We have also developed a high performance broadband (BB) In(0.26) Ga(0.74) As/Al(x) Ga(1-x)As QWIP using a linearly graded (LGB) Al(x) Ga(1-x) As barrier for LWIR detection. Theoretical study on the enhancement of quantum efficiency in a QWIP by using photonic crystal structure has also been carried out in this report.
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A New Two-Color Infrared Photodetector Design Using INGAAS/INALAS Coupled Quantum Wells by :
Download or read book A New Two-Color Infrared Photodetector Design Using INGAAS/INALAS Coupled Quantum Wells written by and published by . This book was released on 1999 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U. S. Army Research Laboratory (ARL) in collaboration with a number of industry and university partners is developing a new generation of sensors that can perform advanced signal processing functions over a very wide range of wavelengths (e.g. from the ultraviolet to the millimeter-wave region of the spectrum).
Book Synopsis Corrugated Quantum Well Infrared Photodetectors and Arrays by :
Download or read book Corrugated Quantum Well Infrared Photodetectors and Arrays written by and published by . This book was released on 1999 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum well infrared photodetectors (QWIPs) have many advantages in infrared detection, mainly due to the mature Ill-V material technology. The employment of the corrugation structure further advances the technology by providing a simple, yet efficient light-coupling scheme. A C-QWIP enjoys the same flexibility as a detector with intrinsic normal incident absorption. In this paper, we will discuss the utilities of C-QWIPs in different applications, including two-color detection and polarization-sensitive detection. Besides practical applications, C-QWIPs are also useful in detector characterization. They can be used for measuring the absorption coefficient of light propagating parallel to the layers under bias and providing information on the energy resolved photoconductive gain. These two quantities have never been measured before. Based on the corrugation design, we have made several modifications that further improve the detector sensitivity without increasing its complexity. Other than the C-QWIP structure, we also continue searching for other sensitive detector architectures. In a quantum grid infrared photodetector, 3-dimensional electron confinement can be achieved, with which the detector is able to absorb light in all directions. At the same time, the photoconductive gain can also be improved. We further improve the design using a blazed structure. All the experimental results are supported by a rigorous electromagnetic modal transmission-line theory developed especially for these types of structures. Preliminary thermal imaging using C-QWIP FPAs validates the advantages of the present approach.
Book Synopsis Asymmetric Quantum Well Structures for Enhanced Infrared Photon Absorption by : Mehjabeen Akhtar Khan
Download or read book Asymmetric Quantum Well Structures for Enhanced Infrared Photon Absorption written by Mehjabeen Akhtar Khan and published by . This book was released on 2013 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compared to inter-band transition for photon absorption in a quantum wells, intra-band (or inter-subband) transitions in heterojunction (GaAs/InP) quantum wells can provide access to a broader range of wavelengths for detector design, specifically detectors operating in the mid infrared region of spectrum (4-12 [micro]m) and beyond is possible. These quantum wells not only provide great flexibility in optimizing the Eigen energy levels or wavefunctions, and inter-subband optical matrix elements determining the corresponding transition probability, but also allow controlling electron-phonon scattering rates and thus electron lifetime. The research presented in this dissertation investigates asymmetric quantum well structures formed through III-V semiconductor material system such as AlGaAs/ InxGa(1-x)As/InyGa(1-y) As/AlGaAs that can further improve the responsivity through higher carrier mobility. Asymmetry is introduced by using multiple materials to form the well region. The advantage of exploring stepped quantum well structure stems from experimental evidence that such structures are capable of absorbing normal incidence and thus eliminates the requirement of incorporating additional optical coupling schemes such as grating structures. An important contribution of this research is the development of an analytical model to analyze single or multiple quantum well structures to quantify photon absorption. The physical model developed in this work is based on non-equilibrium Green's function (NEGF), Fermi's golden rule and quantum mechanical wave impedance concept. The approach has two distinct advantages. First, it is accurate, easily programmable and yet computationally efficient. Second, it facilitates quantifying the broadening of states resulting from both photon absorption and tunneling, which provides important insight for improving detection efficiency. Instead of being presented through calculations, such broadening has been simply assumed in previously reported works. The method developed in this research provides an efficient methodology to quantify the absorption rate of photons with different polarizations. The study looks into the design and analysis of the wells to enhance infrared radiation detection, and suggests mechanisms to optimize the structures in terms of material choice, composition, structural geometry and applied voltages. The high electron mobility and hence drift velocity in InGaAs ( >5×106cm/s), along with low carrier recapture lifetime, is expected to improve the detection speed of the device. Unlike GaAs/AlGaAs, the lattice mismatch at InGaAs/AlGaAs interface is likely to introduce strain in the structure. The effect of such strain as well as the layer thickness is taken into account in this work. Also, a methodology for achieving voltage tenability, i.e. the ability to detect different wavelengths at different bias voltages has been investigated. Although both n-type and p-type systems have potential for optoelectronic devices, n-type quantum wells are more advantageous because of their nearly parabolic sub-band structure. As for material consideration, direct band gap material based systems, such as AlGaAs/InGaAs and AlGaAs/GaAs, have been found to be particularly suitable for n-type QWIP photodetectors. The reason being that the electrons in such materials occupy states around the [gamma]valley where the effective mass is smaller and therefore mobility is higher; a condition which leads to higher photoresponsivity. Moreover such systems allow the possibility of highly stable device operation owing to the insensitivity of intra-band transition energies to temperature fluctuation and reduced influence of Auger recombination.
