?Which one of the following statement(s) is false A substitution impurity in donor and acceptor atoms does not cause any disturbances in the crystal lattice of semiconducting material. In an n-type semiconductor, the free electrons concentration approximately equals the density of donor atoms Each donor atom contributes two free electrons to semiconducting crystal lattice. Mobility of charge carriers equals its average speed v divided by the applied electric field E.

Exercises 1. A silicon p-n junction has the hole and electron resistivity are 0.001 .m, 0.004 .m respectively in T-250 °K. The intrinsic carrier density is 6.2×10¹0 m³, the electron and hole diffusion length are 1.8×104 m, 1.1×104 m respectively, and th=8 µs. Find reverse saturation current density. 2. Given a Si diode with the following physical ch/s the doping concentration in the p-type is 2.25×10¹7 cm³ and in the n-type is 2.25×10¹4 cm³, junction area is 2×10³ cm², life time of hole in n-region=10 µs, life time of electron in p-region =50 µs, hole and electron mobilities are 600 cm³V's¹ and 2100 cm²V¹s¹ respectively, the intrinsic carrier concentration is 1.4x100 cm³ and the voltage is 0.66 v operation at room temperature. Calculate Jp(0) and Jn(0) then calculate the total diode current. 3. A silicon p-n junction has energy of C.B. and V.B. are 0.9 eV, 0.1 eV respectively at 200 K. the hole and electron mobility, resistivity are 0.16 m²/V.s, 0.36 m²/V.s, 0.0025 92.m and 0.005 2.m.…

Q?: Fill in the following blanks with suitable words : 1. Conductivity of a material depends on: and 2. _can break the bonds in semiconductor crystals and create free electrons. 3. Mobility and Sheet resistance in semiconductor are measured by 4. Name of the force which bend electron trajectories in magnetic field At room temperature, the current in an intrinsic semiconductor is due to is unevenly doped 7. During reverse bias of the diode there is a small current of the order of micro 6 Each semiconductor material in a ampere due to

A. Why does the conductivity of a semiconductor and some insulators change with impurity content? Compare this with the behaviour of metallic conductors. B. Discuss the location of the Fermi levels of intrinsic and extrinsic (n-type and p-type) semiconductors in low temperature and high temperature ranges. C. Discuss why the structure of the p-n junction is so important to modern technologies that impact our daily life.

A semiconductor junction diode, we can say that: a) The diode is composed of two types of crystal, one positive side (Anode) and the other P-type (Cathode) side, allowing the flow of charge from N to P.b) It is an electronic component that has two terminals, the Anode (with material of type N - Electrons) and Cathode (with material of type P - Gaps), which allows the flow of charge from P to N.c) It is the union of a P-type crystal and an N-type crystal, thus creating a PN junction, thus creating a simple solid-state device, the junction semiconductor diode.d) At a temperature of 25 degrees Celsius, the depletion barrier has a potential barrier, which for silicon is 0.7 volts and for germanium it is 0.3 volts.e) None of the above options is correct. Choose one of the alternatives

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Q1/Fill in the following blanks and explain the solution steps in detail for studies that require a mathematical solution 1-The charge carriers in conductors are 2- Approximately in a pure semiconductor, the distance between the Versese plane and the tactile bundle is And the Atorement Package 3- Electron density and hole in a pure semiconductor varies with change 4- The majority of charge carriers in the p-type semiconductor in 5- Fermi level in semiconductor non-negative type approaching from From 6- The current of saturation depends on 7-A wide area arises in the area of depletion because this area is treated as The charge carriers in semiconductors are. According to the equation And the carriers of the n type are The distance between the delivery package While in semi-conductor non-negative type approaches

4 - The figure below shows a part of the energy band diagram of a p-n semiconductor junction. According to the situation shown in the figure, in the equilibrium condition, we can identify the currents as follows: *image attached* ( ) i1:hole diffusion current, i2:electron drift current, i3:hole drift current and i4:electron diffusion current. ( ) i1:hole drift current, i2:electron diffusion current, i3:hole diffusion current and i4:electron drift current. ( ) i1:electron diffusion current, i2:electron diffusion current, i3:hole drift current and i4:hole drift current. ( ) i1:electron drift current, i2:electron diffusion current, i3:hole diffusion current and i4:hole drift current. ( ) i1:hole drift current, i2:electron drift current, i3:hole diffusion current and i4:electron diffusion current.

8. Each of the three insulators forming a string has a self capacitance of C farad The shunt capacitance of each insulator is 02C to earth and 0-1 C to line. A guard-ring increases the capacitance of line of the metal work of the lowest insulator to 0-3 C. Calculate the string efficiency of the arrangement: )with the guard ring. (7) without guard ring. 10 95% () 86 13%|

semiconductors