Let a bar of silicon have an intrinsic concentration of 1010 cm3. May 07, 2020 cbse syllabus for class 12 physics 202021. The text covers a wide range of important phenomena in semiconductors, from the simple to the advanced. Free pdf download of hc verma solutions for class 12 physics part2 chapter 45 semiconductors and semiconductor devices solved by expert physics teachers on.
They are less conductive than metals, but differ from metals in that, as a semiconductor heats up, its conductivity rises. In electronics and semiconductor physics, the law of mass action is a relation about the concentrations of free electrons and electron holes under thermal. Pdf mass action and conservation of current researchgate. The reason why your mental image of a semiconductor doesnt really help here, is because its actually impossible to distinguish whether a free. The application of the thermodynamical law of mass action to the calculation of. Ravindran, phy02e semiconductor physics, 26 december 2012. Regardless of doping, the product of electron and hole densities is a constant at equilibrium. Multiplying the expressions for the electron and hole densities in a nondegenerate semiconductor yields.
In a semiconductor the law of mass action states that the product of the electron concentration and the hole concentration is always equal to the square of the intrinsic carrier concentration at a given temperature, i. His book physics of semiconductor devices wiley 1969, 2nd ed, 1981 is the most cited work in contemporary engineering and applied science publications over 12,000 citations from isi press. The physics of semiconductors requires little or no prior knowledge of solidstate physics and evolved from a highly regarded twosemester course. In intrinsic semiconductors fermi level is always lies between valence band and conduction band. During doping, impurity atoms are introduced to an intrinsic semiconductor. It states that, under thermal equilibrium, the product of the free electron concentration and the free hole concentration is equal to a constant square of intrinsic carrier concentration. The law of mass action states that the product of number of electrons in the conduction band and the number of holes in the valence band is constant at a fixed temperature and is independent of amount of donor and acceptor impurity added. Impurity atoms act as either donors or acceptors to the intrinsic semiconduc.
I want to start studying about physics of semiconductors. For example, in the years since the publication of the. Engineering physics pdf notes enginering physics notes. So we can consider the crystal to have an atomic spacing. Chargecarrier equilibrium in semiconductors according to the. Drift velocity, mobility and conductivity of intrinsic semiconductors 5. Law of mass action relates concentration of reactants. Browse other questions tagged quantummechanics condensedmatter temperature semiconductorphysics electronicbandtheory or ask your own question. May 09, 2015 typically, the dopant concentration is at least 47 orders of magnitude 107 larger than the intrinsic concentration. Is the principle of mass action law applicable in a pn. Lecture 2 semiconductor physics i september, 2005 contents.
You should know that a thorough concept of class 11 and class 12 physics to score better marks in the various entrance exam. Impurity atoms are atoms of a different element than the atoms of the intrinsic semiconductor. Cbse syllabus for class 12 physics 20202021 physics. The law of mass action is applied for both intrinsic and extrinsic semiconductors. Solid state physics is written as per the core module syllabus of the major universities and targets undergraduate b. A typical semiconductors conductivity the degree to which it conducts electricity depends on imperfections in the material such as lattice defects, added impurities, and external conditions such as applied electric fields. Law of mass action in hindi analog electronics tech. All the exercise of chapter 45 semiconductors and semiconductor devices questions with solutions to help you to revise complete syllabus and score more marks.
The law of mass action describes how the velocity of a chemical reaction is related to the molecular concentrations of the reactants. Class 12electronic devices 20 days pledge important formulas in solid state physics, summary at the end of vdo, semiconductor, physics thank you for watching, liking. When an intrinsic semiconductor is doped with a dopor impurity like phosphorus, electron concentration will increase, due to the surplus electron provided by each of the doper atom. Physics 301 30nov2005 261 semiconductor basics in solids, the electron energy levels are organized into bands. Physics notes class 12 pdf r k maliks newton classes.
What is the theory behind mass action law in doped. Although a semiconductor has many physical properties, semiconductor name. It states that product of concentration of majority and minority carrier is constant at fixed temperature. This constant depends on the thermal energy of the system i. The reader is assumed to have a basic command of mathematics and some elementary knowledge of solid state physics. Most semiconductors are formed from elements from groups ii, iii, vi, v, vi of the periodic table. This book is based on a twosemester semiconductor physics course.
Molecular physics and living matter physics alexander g. Medical physics in questions and answers 6 angle acceleration. Semiconductor physics may become the replacement for pankoves older book. Law of mass action which says that product of electron and hole concentrations is constant for a semiconductor in equilibrium. My book states that this law is valid for extrinsic semiconductors with impurities as well as for intrinsic semiconductors. The topics have been dealt with precision and provide adequate knowledge of the subject. In the third edition several topics are extended and treated in more depth including surfaces, disordered materials, amorphous semiconductors, polarons, thermopower and noise. This book presents a detailed description of the basic semiconductor physics. The equation is true for both intrinsic and extrinsic semiconductors and tells 2 important facts about extrinsic semiconductors. Jones sandia national laboratories albuquerque, new mexico the lyotropic state of matter. The book is aimed at upperlevelundergraduate and graduate courses on semiconductor physics, solidstate physics and physical electronics. Basic laws of physics that govern our universe can be categorized in two ways. Feb 09, 2015 during doping, impurity atoms are introduced to an intrinsic semiconductor. Now dope it with a donor of concentration 1016 cm3.
Pdf the law of mass action does not force a series of chemical reactions to have the same current flow everywhere. The book uses lecture style in explaining the concepts which would facilitate easy understanding of the concepts. It underpins several types of biochemical, physiological, and pharmacological phenomena. He has authored or coauthored over 150 technical papers, and has written, edited, and contributed to 24 books. Semiconductor physics and materialsintrinsic and extrinsic semiconductors, conduction mechanism in extrinsic semiconductors, carrier concentrations, drift and diffusion mechanisms, drift and diffusion current densities, excess carriers, recombination process, mean carrier lifetime, conductivity, mobility, mass action law, einstein relationship. Please give me suggestions about a book that can explain physics of semiconductor in general and clear fashion.
The course also wraps in itself our experience in successfully. The law of mass action states that the rate of a reaction is proportional to the. The elements most commonly used in semiconducting devices are silicon and germanium donors, acceptorselectrons, holes. Typically, the dopant concentration is at least 47 orders of magnitude 107 larger than the intrinsic concentration. Applications illustrated with computergenerated animations. The law of mass action also has implications in semiconductor physics. Law of mass action and intrinsic carrier concentration 6. Carrier concentration and fermi level for intrinsic semiconductors.
Lawofmass action relates concentration of reactants. The atoms of semiconductor elements have exactly four valence electrons. This law states the relation between concentrations of minority and majority carriers at a constant temperature. Full text of physics of semiconductor devices see other formats. Laws of physics and applications of all physics laws byjus. The physics of semiconductors an introduction including. Introduction in order to understand the physics of semiconductor sc devices, we should first learn how atoms bond together to form the solids. The book presents a broad survey of modern areas in semiconductor physics and technology with lots of figures and diagrams.
In electronics and semiconductor physics, the law of mass action is a relation about the concentrations of free electrons and electron holes under thermal equilibrium. It is equal to the product of mass m and centripetal acceleration ad, i. Physics stack exchange is a question and answer site for active researchers, academics and students of physics. Semiconductor physics and material science have continued to prosper and to break new ground. Just ask brittney spears, a semiconductor is a material whose electrical conductivity is between that of a conductor and an insulator. Hc verma class 12 physics part2 solutions for chapter 45. Classical physics that deals with us, the surrounding environment and the observable universe around us.
Class 12 physics is the most important subject for the academic exams 202021. Browse other questions tagged quantummechanics condensedmatter temperature semiconductor physics electronicbandtheory or ask your own question. Engineering physics agricultural engineering pdf book. Because of these four valence electrons, the semiconductor elements do have some special electrical characteristics and properties, which make them useful in using extensively in electronic circuit elements like diodes, transistors, scrs, etc. Massaction law of semiconductors electrical engineering. For extrinsic semiconductor the law of mass action states that the product of. Newtons first law, newtons second law, newtons third law, gravity, the solar system, the age of calculus, law of conservation of momentum, conservation of energy and pressure. Imagine a regular crystal lattice composed of identical atoms. The course also wraps in itself our experience in successfully training thousands of students in classrooms over a decade. Book search tips selecting this option will search all publications across the. Apart from this, there is also atomic physics that deals with subatomic particles and their interactions quantum mechanics. Imagine that the size of the crystal can be varied. With a better concept on the latest syllabus, you can secure good marks. A semiconductor has a conductivity between that of a conductor and an insulator.