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Semiconductor Heterostructures and Their Application
Zhores Alferov The History of Semiconductor Heterostructures Reserch: from Early Double Heterostructure Concept to Modern Quantum Dot Structures St Petersburg Academic University — Nanotechnology Research and Education Centre RAS • Introduction • Transistor discovery • Discovery of laser-maser principle and birth of optoelectronics • Heterostructure early proposals • Double heterostructure concept: classical, quantum well and superlattice heterostructure. “God-made” and “Man-made” crystals • Heterostructure electronics • Quantum dot heterostructures and development of quantum dot lasers • Future trends in heterostructure technology • Summary 2 The Nobel Prize in Physics 1956 "for their researches on semiconductors and their discovery of the transistor effect" William Bradford John Walter Houser Shockley Bardeen Brattain 1910–1989 1908–1991 1902–1987 3 4 5 6 W. Shockley and A. Ioffe. Prague. 1960. 7 The Nobel Prize in Physics 1964 "for fundamental work in the field of quantum electronics, which has led to the construction of oscillators and amplifiers based on the maser-laser principle" Charles Hard Nicolay Aleksandr Townes Basov Prokhorov b. 1915 1922–2001 1916–2002 8 9 Proposals of semiconductor injection lasers • N. Basov, O. Krochin and Yu. Popov (Lebedev Institute, USSR Academy of Sciences, Moscow) JETP, 40, 1879 (1961) • M.G.A. Bernard and G. Duraffourg (Centre National d’Etudes des Telecommunications, Issy-les-Moulineaux, Seine) Physica Status Solidi, 1, 699 (1961) 10 Lasers and LEDs on p–n junctions • January 1962: observations -
Semiconductor Science and Leds
Optoelectronics EE/OPE 451, OPT 444 Fall 2009 Section 1: T/Th 9:30- 10:55 PM John D. Williams, Ph.D. Department of Electrical and Computer Engineering 406 Optics Building - UAHuntsville, Huntsville, AL 35899 Ph. (256) 824-2898 email: [email protected] Office Hours: Tues/Thurs 2-3PM JDW, ECE Fall 2009 SEMICONDUCTOR SCIENCE AND LIGHT EMITTING DIODES • 3.1 Semiconductor Concepts and Energy Bands – A. Energy Band Diagrams – B. Semiconductor Statistics – C. Extrinsic Semiconductors – D. Compensation Doping – E. Degenerate and Nondegenerate Semiconductors – F. Energy Band Diagrams in an Applied Field • 3.2 Direct and Indirect Bandgap Semiconductors: E-k Diagrams • 3.3 pn Junction Principles – A. Open Circuit – B. Forward Bias – C. Reverse Bias – D. Depletion Layer Capacitance – E. Recombination Lifetime • 3.4 The pn Junction Band Diagram – A. Open Circuit – B. Forward and Reverse Bias • 3.5 Light Emitting Diodes – A. Principles – B. Device Structures • 3.6 LED Materials • 3.7 Heterojunction High Intensity LEDs Prentice-Hall Inc. • 3.8 LED Characteristics © 2001 S.O. Kasap • 3.9 LEDs for Optical Fiber Communications ISBN: 0-201-61087-6 • Chapter 3 Homework Problems: 1-11 http://photonics.usask.ca/ Energy Band Diagrams • Quantization of the atom • Lone atoms act like infinite potential wells in which bound electrons oscillate within allowed states at particular well defined energies • The Schrödinger equation is used to define these allowed energy states 2 2m e E V (x) 0 x2 E = energy, V = potential energy • Solutions are in the form of -
A Self-Consistent Static Model of the Double-Heterostructure Laser
IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. QE-17, NO. 9, SEPTEMBER 1981 1941 A Self-Consistent Static Model of the Double-Heterostructure Laser Abstract-A new static model of the double-heterostructure laser is even as an approximation, neglects twovery important effects: presentedwhich treats the p-njunction in the laser in a consistent first,the effect on the electricad characteristics oflateral manner.The .soiution makes use of thefinite-element method to treat complex diodegeometries. The model is valid above lasing thresh- carrier drift and diffusion and, second, the saturation of junc- old cdshows both the saturationin the diode junction voltageat tionvoltage (and carrier populations) associated with lasing thresholdas well as lateral mode shifts associated with spatial hole threshold. A more reasonable condition to apply to the diode burning.Several geometries have been analyzed and somespecific junction in the double-heterostructure laser is to assume the results are presented as illustration. continuity of the carrier quasi-Fermi levels across the hetero- junction interfaces. Thisassumption leads naturally to the I.INTRODUCTION saturationof the diode voltage at lasing threshold,and is OUBLE-HETEROSTRUCTURE injection lasershave consistent with semiconductor physics. However, the use of Drecently become objects of intense interest as compact, this model of the diode junction requires the use of a different highly efficient sources of coherent light. With this in mind, solution method from that ofprevious models. laser diode modeling is potentially a tool of great value, both Another model specifically designed to treat the behavior of to understand the effects seen in real laser diodes as well as to a narrow planar stripe laser treats the diode junction in this predict and possibly optimize the behavior of as yet unfabri- manner using a highly simplified geometry [7] . -
1 Semiconductors, Alloys, Heterostructures
1 Semiconductors, alloys, heterostructures 1.1 Introducing semiconductors Single-crystal semiconductors have a particularly important place in optoelectronics, since they are the starting material for high-quality sources, receivers and amplifiers. Other materials, however, can be relevant to some device classes: polycrystalline or amorphous semiconductors can be exploited in light-emitting diodes (LEDs) and solar cells; dielectrics (also amorphous) are the basis for passive devices (e.g., waveguides and optical fibers); and piezoelectric (ferroelectric) crystals such as lithium niobate are the enabling material for a class of electrooptic (EO) modulators. Moreover, polymers have been recently exploited in the development of active and passive optoelectronic devices, such as emitters, detectors, and waveguides (e.g., fibers). Nevertheless, the peculiar role of single-crystal semiconductors justifies the greater attention paid here to this material class with respect to other optoelectronic materials. From the standpoint of electron properties, semiconductors are an intermediate step between insulators and conductors. The electronic structure of crystals generally includes a set of allowed energy bands, that electrons populate according to the rules of quantum mechanics. The two topmost energy bands are the valence and conduction band, respectively, see Fig. 1.1. At some energy above the conduction band, we find the vacuum level, i.e., the energy of an electron free to leave the crystal. In insulators,the valence band (which hosts the electrons participating to the chemical bonds) is separated from the conduction band by a large energy gap Eg, of the order of a few electronvolts (eV). Due to the large gap, an extremely small number of electrons have enough energy to be promoted to the conduction band, where they could take part into electrical con- duction. -
Doping Concentration Effect on Performance of Single QW Double-Heterostructure Ingan/Algan Light Emitting Diode
EPJ Web of Conferences 162, 01037 (2017) DOI: 10.1051/epjconf/201716201037 InCAPE2017 Doping concentration effect on performance of single QW double-heterostructure InGaN/AlGaN light emitting diode N. Syafira Abdul Halim1,*, M.Halim A. Wahid1, N. Azura M. Ahmad Hambali1, Shanise Rashid1, and Mukhzeer M.Shahimin2 1Semiconductor Photonics & Integrated Lightwave Systems (SPILS), School of Microelectronic Engineering, Universiti Malaysia Perlis, Pauh Putra Campus, 02600 Malaysia. 2Department of Electrical and Electronic Engineering, Faculty of Engineering, National Defence University of Malaysia (UPNM), Kem Sungai Besi, 57000 Kuala Lumpur. Abstract. Light emitting diode (LED) employed a numerous applications such as displaying information, communication, sensing, illumination and lighting. In this paper, InGaN/AlGaN based on one quantum well (1QW) light emitting diode (LED) is modeled and studied numerically by using COMSOL Multiphysics 5.1 version. We have selected In0.06Ga0.94N as the active layer with thickness 50nm sandwiched between 0.15µm thick layers of p and n-type Al0.15Ga0.85N of cladding layers. We investigated an effect of doping concentration on InGaN/AlGaN double heterostructure of light-emitting diode (LED). Thus, energy levels, carrier concentration, electron concentration and forward voltage (IV) are extracted from the simulation results. As the doping concentration is increasing, the performance of threshold voltage, Vth on one quantum well (1QW) is also increases from 2.8V to 3.1V. 1 Introduction dislocation density. In this context, the improvement of increasing doping concentration in gallium nitride (GaN) Wide band gap gallium nitride (GaN) based LED structure has a great importance for better semiconductor device has become a great potential of performances in GaN LED structure. -
Light Emitting Diode
Module 6 : Light Emitting Diode Lecture : Light Emitting Diode part - I Objectives In this lecture you will learn the following Introduction to Light Emitting Diode (LED) Principle of LED - p-n Homojunction Double Heterojunctions LED Materials - Direct and Indirect Band Gaps LED Circuit 1.1Introduction A light emitting diode (LED) is a device which converts electrical energy to light energy. LEDs are preferred light sources for short distance (local area) optical fiber network because they: are inexpensive, robust and have long life (the long life of an LED is primarily due to its being a cold device, i.e. its operating temperature being much lower than that of, say, an incandescent lamp), can be modulated (i.e. switched on and off) at high speeds (this property of an LED is also due to its being a cold device as it does not have to overcome thermal inertia), couple enough output power over a small area to couple to fibers (though the output spectrum is wider than other sources such as laser diodes). The circuit symbol of an LED is shown alongside. There are two leads, a short one, cathode, labelled or k and a long one, anode, labelled a or +. 1.2 Principle of LED - p-n Homojunction An LED is essentially a p-n junction diode. It may be recalled that a p- type semiconductor is made by doping an intrinsic semiconductor with acceptor impurities while an n- type is made by doping with donor impurities. Ionization of carriers from the localized levels near the bottom of the conduction band provides electron carriers in the conduction band. -
REVIEW the History and Future of Semiconductor Heterostructures
REVIEW The history and future of semiconductor heterostructures Zh. I. Alferov A. F. Ioffe Physicotechnical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia ~Submitted July 22, 1997; accepted for publication July 27, 1997! Fiz. Tekh. Poluprovodn. 32, 1–18 ~January 1998! The history of the development of semiconductor heterostructures and their applications in various electron devices is presented, along with a brief historical survey of the physics, production technology, and applications of quantum wells and superlattices. Advances in recent years in the fabrication of structures utilizing quantum wires and especially quantum dots are discussed. An outline of future trends and prospects for the development and application of these latest types of heterostructures is presented. © 1998 American Institute of Physics. @S1063-7826~98!00101-X# 1. INTRODUCTION heterostructures.1 In the same year A. F. Ioffe and Ya. I. It would be very difficult today to imagine solid state Frenkel’ formulated the theory of current rectification at a physics without semiconductor heterostructures. Semicon- metal-semiconductor interface, based on the tunneling 2 In 1931 and in 1936 Frenkel’ published his cel- ductor heterostructures and especially double heterostruc- effect. ebrated papers,3 tures, including quantum wells, quantum wires, and quantum in which he predicted excitonic phenomena dots, currently comprise the object of investigation of two and, naming them as such, developed the theory of excitons thirds of all research groups in the physics of semiconduc- in semiconductor heterostructures. Excitons were eventually 4 The first diffu- tors. detected experimentally by Gross in 1951. sion theory of a rectifying p – n heterojunction, laying the While the feasibility of controlling the type of conduc- foundation for W. -
Outline • In-Plane Laser Diodes, Cont. • Vertical Cavity, Surface Emitting Lasers
6.772/SMA5111 - Compound Semiconductors Lecture 21 - Laser Diodes - 2 - Outline • In-plane laser diodes, cont. (continuing from Lect. 20) Cavity design (in-plane geometries) Vertical structure: homojunction, double heterojunction, quantum well, quantum cascade Lateral definition: stripe contact, buried heterostructure, shallow rib End-mirror design: cleaved facet, etched facet, DFB, DBR Output beam shaping • Vertical cavity, surface emitting lasers (VCSELs)� Basic concept, design and fabrication issues� Structures, technologies� • In-plane surface emitting lasers� Deflecting, etched mirrors� Second order gratings; holographic elements� • Modulating laser diodes� Small signal modulatioin� Step change response� C. G. Fonstad, 4/03 Lecture 21 - Slide 1� Laser diodes: vertical design evolution� Double heterostructure:� The first major advance in laser� diode design was the double� heterostructure geometry� which confines the carriers� and the light to the same� region.� The threshold current density is (Image deleted)� approximately� qn d J = crit See Fig. 15-13(a) in: Yariv, A., Optical Electronics, th t New York: Holt, Rinehart and Winston, 1985. min As predicted, and shown to the� right, Jth decreases linearly� with d until the guide layer is� too thin to confine the light, at� which point the overlap� decreases and the threshold� increases.� C. G. Fonstad, 4/03 Lecture 21 -Slide 2 Laser diodes: vertical design evolution� Double heterostructure:� carriers and light are confined� by the same narrow bandgap� layer. The threshold decreases� with d until the optical mode� spills out.� Separate confinement DH:� the waveguide and carrier� confinement functions are done� by different layers. The overlap� is less, but the threshold is still� reduced.� Quantum well: the overlap is less than in SCDH, but there is a net win because the quantum well transitions are stronger. -
Calibration of Polarization Fields and Electro-Optical Response of Group
applied sciences Article Calibration of Polarization Fields and Electro-Optical Response of Group-III Nitride Based c-Plane Quantum-Well Heterostructures by Application of Electro-Modulation Techniques Dimitra N. Papadimitriou 1,2 1 National Technical University of Athens, Heroon Polytechniou 9, GR-15780 Athens, Greece; [email protected]; Tel.: +30-6974149515 2 Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstr. 36, DE-10623 Berlin, Germany Received: 15 November 2019; Accepted: 20 December 2019; Published: 27 December 2019 Abstract: The polarization fields and electro-optical response of PIN-diodes based on nearly lattice-matched InGaN/GaN and InAlN/GaN double heterostructure quantum wells grown on (0001) sapphire substrates by metalorganic vapor phase epitaxy were experimentally quantified. Dependent on the indium content and the applied voltage, an intense near ultra-violet emission was observed from GaN (with fundamental energy gap Eg = 3.4 eV) in the electroluminescence (EL) spectra of the InGaN/GaN and InAlN/GaN PIN-diodes. In addition, in the electroreflectance (ER) spectra of the GaN barrier structure of InAlN/GaN diodes, the three valence-split bands, G9, G7+, and G7 , could selectively be excited by varying the applied AC voltage, which opens new possibilities − for the fine adjustment of UV emission components in deep well/shallow barrier DHS. The internal polarization field E = 5.4 1.6 MV/cm extracted from the ER spectra of the In Al N/GaN DHS pol ± 0.21 0.79 is in excellent agreement with the literature value of capacitance-voltage measurements (CVM) Epol = 5.1 0.8 MV/cm. The strength and direction of the polarization field E = 2.3 0.3 MV/cm of the ± pol − ± (0001) In0.055Ga0.945N/GaN DHS determined, under flat-barrier conditions, from the Franz-Keldysh oscillations (FKOs) of the electro-optically modulated field are also in agreement with the CVM results Epol = 1.2 0.4 MV/cm. -
The Double Heterostructure Concept and Its Applications in Physics, Electronics, and Technology*
REVIEWS OF MODERN PHYSICS, VOLUME 73, JULY 2001 Nobel Lecture: The double heterostructure concept and its applications in physics, electronics, and technology* Zhores I. Alferov A. F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation (Published 22 October 2001) I. INTRODUCTION enon (Frenkel and Ioffe, 1932; Zhuze and Kurchatov, 1932a, 1932b). In 1931 and 1936 Frenkel published his It is impossible to imagine now modern solid-state famous articles where he predicted, gave the name, and physics without semiconductor heterostructures. Semi- developed the theory of excitons in semiconductors, and conductor heterostructures and, particularly, double het- E. F. Gross experimentally discovered excitons in 1951 erostructures, including quantum wells, wires, and dots, (Frenkel, 1931, 1936; Gross and Karryev, 1952a, 1952b). are today the subject of research of two-thirds of the The first diffusion theory of p-n heterojunction rectifi- semiconductor physics community. cation, which became the base for W. Shockley’s p-n The ability to control the type of conductivity of a junction theory, was published by B. I. Davydov in 1939 semiconductor material by doping with various impuri- (Davydov, 1939). Because of Ioffe’s initiative in the late ties and the idea of injecting nonequilibrium charge car- 1940s at the Physico-Technical Institute, research into riers could be said to be the seeds from which semicon- intermetallic compounds was begun. Theoretical predic- 3 5 ductor electronics developed. Heterostructures tion of semiconductor properties in A B compounds developed from these beginnings, making it possible to and their subsequent experimental discovery were done solve the considerably more general problem of control- independently by H. -
Semiconductor Lasers 13
CHAPTER 13 Semiconductor Lasers 13 Semiconductor Lasers 13.1 Introduction The semiconductor laser, in various forms, is the most widely used of all lasers, it is manufactured in the largest quantities, and is of the greatest practical importance. Every compact disc (CD) player contains one. Much of the world’s long, and medium, distance communication takes place over optical fibers along which propagate the beams from semiconductor lasers. These lasers operate by using the jumps in energy that can occur when electrons travel between semiconductors containing different types and levels of controlled impurities (called dopants). In this chapter we will discuss the basic semiconductor physics that is necessary to understand how these lasers work, and how various aspects of their operation can be controlled and improved. Central to this discussion will be what goes on at the junction between p-andn-type semiconductors. The ability to grow precisely-doped single- and multi-layer semiconductor materials and fabricate devices of various forms – at a level that could be called molecular engineering – has allowed the development of many types of structure that make efficient semiconductor lasers. In some respects the radiation from semiconductor lasers is far from ideal, its coherence properties are far from perfect, being intermediate between those of a low pressure gas laser and an incoherent line source. We will discuss how these coherence properties can be controlled in semiconductor lasers. 310 Semiconductor Lasers Fig. 13.1. 13.2 Semiconductor Physics Background When atoms combine to form a solid the sharply defined energy states that we associate with free atoms, such as in a gas, broaden considerably because of the large number of interactions between an atom and its neighbors. -
Laser Physics 19 Semiconductor Lasers
Laser Physics 1199.. Semiconductor lasers Maák Pál Atomic Physics Department 1 Semiconductor lasers Basic properties • Operation between conductive and valence bands of the semiconductor material • Direct current pumping • Efficiency typically > 30% • Small dimensions (0.1 x 1-2 x 150-200 µm3 volume, cross section in the range of µm2) Semiconductor materials – energy bands, charge carriers T = 0 K Empty conduction band Band gap < 3 eV Filled valence band -13 Pumping: After ~ 10 s rearrangement within band Ɣ Ɣ Ɣ Ɣ Conduction band ɨ Valence band ɨ 2 ɨ ɨ Laser Physics 19 Semiconductor lasers Semiconductor materials – energy bands, charge carriers (cont.) Energy of free electrons depends on p: 2 2 2 p ! k 2S 31 E , p !k, k , m0 9,110 kg 2m0 2m0 O de Broglie wavelength E – k relation is a simple parabola! In semiconductors electrons and holes move „freely” within the bands. Schrödinger-equation and the crystal structure determine their movements. E – k is a periodic function of the k components: k1, k2, k3. When a1, a2, a3 are the lattice constants, the periods are S/ a1, S/ a2, S/ a3. Close to the edges the E – k function is nearly a parabola: !2k 2 effective masses (c, v – at the conduction band edge E Ec conduction, valence band) 2mc !2k 2 at the valence band edge E E , E E E v 2m v c g 3 v Laser Physics 19 Semiconductor lasers Semiconductor materials – energy bands, charge carriers (cont.) approximation 4 Laser Physics 19 Semiconductor lasers Semiconductor materials – energy bands, charge carriers (cont.) Indirect band gap! Basic difference between Si and GaAs considering interaction with light! Photon momentum << electron momentum! In indirect band gap semiconductor the recombination is not possible with only a photon emission! direct band gap! 5 Laser Physics 19 Semiconductor lasers Semiconductor materials Photon emission in indirect and direct band semiconductors: indirect transition (e.g.