Shut the left side and translate from English into native language. Shut the right side and translate from native language into English
Shut the right side and translate from native language into English
Read the text
| ON SEMICONDUCTORS A semiconductor is often defined as an electric conductor that has a conductivity intermediate between that of an insulator and that of metal. The more important semiconductors are: boron, germanium, silicon, selenium, phosphorus, gray tin and others. The mechanical properties of semiconductors vary greatly. However, in hardness, brittleness, and fracture strength, semiconducting crystals resemble insulating crystals more than they do metals. Besides their electric properties, which in themselves may be of great variety, semiconductors vary in such physical qualities as magnetism, specific heat and thermal conductivity. Semiconductors are widely used in electronics. They challenge vacuum tubes in many applications in the electronic industry. Engineers and physicists are going to solve many engineering problems by means of semiconductors. |
Shut the left side and translate from English into native language.
Shut the right side and translate from native language into Englis
8.4.1.. Finish sentences:
Match the sides
Answer the questions
X. Summarizing XI. Homework-read and translate. Learn the words and terms
ПЛАН ЗАНЯТТЯ 6сем-7
“”200р.
(дата заняття)
Група: МЕЕ
Спеціальність: Електрики
Тема заняття:Полупровідники.
Мета заняття:
ДидактичнаОзнайомити з новими Л О, навчити їх вірно вимовляти та вживати в читанні, мовленні Практикувати у читанні тексту з метою отримання загального розвитку логічного мислення та пам’яті
Виховна Формувати інтерес до майбутньої спеціальності, бажання вдосканалювати свої знання ,формувати самостійність,наполегливість в пошуках нового.за допомогою вивчення англійської мови.
Види заняття: (лекція, семінар, практичне, лабораторне, консультація, курсове, . дипломне проектування тощо) Практичне
Форма проведення заняття: (диспут, евристична бесіда, ділова гра, бінарне або інтеграційне заняття, шоу, конкурс, аукціон, тощо) Бесіда з елементами гри
Міжпредметні зв’язки:
Забезпечуючи «Всуп до фаху » «Фізика», «Інформатика»
.
Забезпечувані «Електротехніка» ,«Електропривід», «Інформаційні системи та мережі». та ін..
Методичне забезпечення:(карта, роздатковий матеріал, кросворди, опорні
конспекти тощо) картки, роздатковий матеріал
Література:
Обов’язкова Коваленко ВЕ англійська мова Вища школа Львів 1972
Додатковакартки
Технічні засоби навчання: (кодоскоп, комп’ютер тощо)
ХІД ЗАНЯТТЯ
I .Організаційний момент: .
Who is on duty today?
Who is absent?
What date is today?
What day of week is today?
II.Ознайомлення студентів з темою та метою заняття:
Today’s topic is Semiconductors. ”:
to recognize new words and expressions,
to understand their meaning and operate by them discussing the text;
to identify main ideas and details from the text;
to participate in common conversational exchanges on the topic of today's lesson.
III. Мотивація навчання:
The knowledge of this topic will increase your outlook and knowledge of some interesting facts about metals, their place in the life, as future specialists you must be well-educated, cultured people. This information will help you in your future profession
IV.Актуалізація опорних знань.
Grammar tests:
V) Уведення в іншомовну атмосферу:
Watch the short video. Try to understand and answer the questions
VI) Активізація ЛO теми заняття:
I'll check your homework.
v) Робота з картками.
VII. Викладення та вивчення нового матеріалу
VIII.Запис плану
1Introduction with a new words
2 Exercises
3.Introduction with a new topic
4 Exercises
5. Reading the text
IX Homework
X.Summarizing
Semiconductors
Semiconductors are defined by their unique electric conductive behavior. Metals are good conductors because at their Fermi level, there is a large density of energetically available states that each electron can occupy. Electrons can move quite freely between energy levels without a high energy cost. Metal conductivity decreases with temperature increase because thermal vibrations of crystal lattice disrupt the free motion of electrons. Insulators, by contrast, are very poor conductors of electricity because there is a large difference in energies (called a band gap) between electron-occupied energy levels and empty energy levels that allow for electron motion.
Insulator conductivity increases with temperature because heat provides energy to promote electrons across the band gap to the higher electron conduction energy levels (called the conduction band). Semiconductors, on the other hand, have an intermediate level of electric conductivity when compared to metals and insulators. Their band gap is small enough that small increase in temperature promotes sufficient number of electrons (to result in measurable currents) from the lowest energy levels (in the valence band) to the conduction band. This creates electron holes, or unoccupied levels, in the valence band, and very loosely held electrons in the conduction band.[5][6] An intrinsic semiconductor is made up ideally of one pure element, typically silicon. At room temperature, the conductivity of intrinsic semiconductors is relatively low. Conductivity is greatly enhanced by a process called doping, in which other elements are added to the intrinsic crystal in very small amounts to create what is called an extrinsic semiconductor. N-type semiconductors are produced when donor atoms, a type of dopant, donate extra electrons to the host. The process of doping introduces energy levels into the band gap; those levels are filled with electrons and lie close to the conduction band so that even slight thermal agitation can release them into the conduction band.[5]
The negative charge of the electrons is balanced by an equivalent positive charge in the center of the impurity atoms. Therefore, the net electrical charge of the semiconductor material is not changed
SEMICONDUCTORS
A transistor is an active semiconductor device with three or more electrodes. By active we mean that the transistor is capable of current gain, voltage, amplification and power gain. A transistor is an electron device in which electronic conduction takes place within a semiconductor.
A semiconductor is an electric conductor with resistivity in the range between metals and insulators, in which the electrical charge carrier concentration increases with increasing temperature over some temperature range.
The resistivities of semiconductors and insulators decrease rapidly with rising temperatures, while those of metals increase relatively slowly. Unlike metals and insulators, the resistivity of semiconductors depends upon the direction of current flow. The direction of easiest current flow or lowest resistivity is called the forward direction, the direction of restricted current flow or highest resistivity is known as the reverse or back direction.
Semiconductors, such as the elements germanium and silicon, possess two types of current carriers, namely, negative electrons and positive holes. A hole is a mobile vacancy in the electronic valence structure of a semiconductor which acts like a positive electronic charge with a positive mass.
1. Listen to the following questions and give short positive or negative answers:
1. Is a semiconductor defined as an electric conductor?
2. Do semiconductors vary greatly in appearance?
3. May transistors replace vacuum tubes?
4. Does the state of substances depend on temperature and pressure?
5. Will you study electronics this year?
6. Have many human activities played a part in scientific inventions?
7. Did the ancients know anything about electricity?
II. Listen to the new words and word combinations (
ХІД ЗАНЯТТЯ
Read and remember