Electrical components, Diode, Transistors are frequently used in electronic devices. By
what materials these components are manufactured? Describe the reasons/ characteristic
of these materials?
1. A diode is formed by joining two equivalently doped P-Type and N-Type
semiconductor.
2. A transistor is created by using three layers rather than the two layers used in a diode.
You can create either an NPN or a PNP sandwich
Today the most common diodes & transistors are made from semiconductor materials
such as silicon or germanium.
In the crystalline lattice structure of Si, the valence electrons of every Si atom are
Locked up in covalent bonds with the valence electrons of four neighboring Si atoms.
– In pure form, Si wafer does not contain any free charge carriers.
– An applied voltage across pure Si wafer does not yield electron flow through the wafer.
– A pure Si wafer is said to act as an insulator.
Pure silicon is an intrinsic semiconductor, which means that unlike metals, it conducts electron
holes and electrons released from atoms by heat
Silicon makes up about 28% of the Earth's crust. It is generally not found on Earth in its free
form, but is usually found in silicate minerals.
Atoms in a pure silicon wafer contains four electrons in outer orbit (called valence
Electrons).
Germanium is another semiconductor material with four valence electrons.
Pure monocrystalline silicon is used to produce silicon wafers used in the semiconductor
industry, in electronics, and in some high-cost and high-efficiency photovoltaic applications.
Pure silicon is an intrinsic semiconductor, which means that unlike metals, it conducts electron
holes and electrons released from atoms by heat; silicon's electrical conductivity increases with
higher temperatures. Pure silicon has too low a conductivity (i.e., too high a resistivity) to be
used as a circuit element in electronics. In practice, pure silicon is doped with small
concentrations of certain other elements, which greatly increase its conductivity and adjust its
electrical response by controlling the number and charge (positive or negative) of activated
carriers. Such control is necessary for transistors, solar cells, semiconductor detectors, and other
semiconductor devices used in the computer industry and other technical applications. In silicon
photonics, silicon can be used as a continuous wave Raman laser medium to produce coherent
light, though it is ineffective as an everyday light source.
One allotrope is in the form of shiny, grayish-black, needle-like crystals, or flat plates. The
second allotrope has no crystal structure and usually occurs as a brown powder. The melting
point of silicon is 1,410°C (2,570°F) and the boiling point is 2,355°F (4,270°F). Its density is
2.33 grams per cubic centimeter.
Chemical properties of silicon - Health effects of silicon - Environmental effects of silicon
Atomic number 14
Electronegativity according to Pauling 1.8
Density 2.33 g.cm -3 at 20
Melting point 1410 °C
Boiling point 3265 °C
what materials these components are manufactured? Describe the reasons/ characteristic
of these materials?
1. A diode is formed by joining two equivalently doped P-Type and N-Type
semiconductor.
2. A transistor is created by using three layers rather than the two layers used in a diode.
You can create either an NPN or a PNP sandwich
Today the most common diodes & transistors are made from semiconductor materials
such as silicon or germanium.
In the crystalline lattice structure of Si, the valence electrons of every Si atom are
Locked up in covalent bonds with the valence electrons of four neighboring Si atoms.
– In pure form, Si wafer does not contain any free charge carriers.
– An applied voltage across pure Si wafer does not yield electron flow through the wafer.
– A pure Si wafer is said to act as an insulator.
Pure silicon is an intrinsic semiconductor, which means that unlike metals, it conducts electron
holes and electrons released from atoms by heat
Silicon makes up about 28% of the Earth's crust. It is generally not found on Earth in its free
form, but is usually found in silicate minerals.
Atoms in a pure silicon wafer contains four electrons in outer orbit (called valence
Electrons).
Germanium is another semiconductor material with four valence electrons.
Pure monocrystalline silicon is used to produce silicon wafers used in the semiconductor
industry, in electronics, and in some high-cost and high-efficiency photovoltaic applications.
Pure silicon is an intrinsic semiconductor, which means that unlike metals, it conducts electron
holes and electrons released from atoms by heat; silicon's electrical conductivity increases with
higher temperatures. Pure silicon has too low a conductivity (i.e., too high a resistivity) to be
used as a circuit element in electronics. In practice, pure silicon is doped with small
concentrations of certain other elements, which greatly increase its conductivity and adjust its
electrical response by controlling the number and charge (positive or negative) of activated
carriers. Such control is necessary for transistors, solar cells, semiconductor detectors, and other
semiconductor devices used in the computer industry and other technical applications. In silicon
photonics, silicon can be used as a continuous wave Raman laser medium to produce coherent
light, though it is ineffective as an everyday light source.
One allotrope is in the form of shiny, grayish-black, needle-like crystals, or flat plates. The
second allotrope has no crystal structure and usually occurs as a brown powder. The melting
point of silicon is 1,410°C (2,570°F) and the boiling point is 2,355°F (4,270°F). Its density is
2.33 grams per cubic centimeter.
Chemical properties of silicon - Health effects of silicon - Environmental effects of silicon
Atomic number 14
Electronegativity according to Pauling 1.8
Density 2.33 g.cm -3 at 20
Melting point 1410 °C
Boiling point 3265 °C
