Simulation 1 Mat_Dev

a) Explain the band structure of an electrical conductor (metal), a semiconductor, and an insulator at 0 K by showing the valence and conduction bands and fermi energy levels. Explain how the electrical conduction takes place in these three types of materials. Give an example for each type of material. b)Explain what n and p-type semiconductors are using their band structures.

A single crystal intrinsic semiconductor is at a temperature of 300K with effective density of states for holes twice that of electrons. The thermal voltage is 26 mV. The intrinsic Fermi level is shifted from mid-bandgap energy level by

Which statement(s) is (are) true about a P-N junction: A. P-N junction consists of n-type and p-type semiconductor materials.B. Free electrons in n-type diffuse across junction to p-type.C. A depletion region formation happens due to electrons and holes moving away from each other due to the electric field.

Take a diode formed by the junction of two type n and p semiconductors. In the figure below is the diagram of the energy bands of these semiconductors, (remember the concept of fermi energy, and knowing that for a pure semiconductor it is in the middle). Based on the figures below, answer a) What is the possible current direction in the direction from p to n or from n to p? b) Explain why the current flow occurs only in one direction.

Where is the Fermi-level of a boron doped Si semiconductor at 77 K, 300 K, and 600 K at full activation of dopants? The Fermi-level shall be related to the intrinsic Fermi-level Ej. (NA = 107 cm3, Eg(Si) = 1.12 ev, m,* = 0.3mo, m,* = 0.5mo.) Sketch the solution.

The linear electron and hole concentration profiles in a 4 um wide region of silicon material is shown in the figure below. The silicon material is subjected to electron injection from the left and hole injection from the right as shown in the figure. Assume that the cross-sectional area of the material ?=1 ??2, electron mobility ??=1312.75 ??2/? ?, and hole mobility ??=463.33 ??2/? ?. Find the total current (to one decimal place) flowing through the material. ?=300?, ?=1.6×10−19 ?, ?=8.62×10−5 ??/?, ?=1.38×10−23 ?/?, and 1 ??=1.6×10−19 ?.   Explain how depletion and diffusion capacitances differ

Describe the temperature dependence of electrical conductivity in heavily doped extrinsic semiconductors and schematically sketch the temperature dependent electrical conductivity that includes the following regions: freeze-out, extrinsic, and intrinsic.

When a p-and n-type semiconductor are joined at an interface their Fermi energies equilibriate. If we extend this thinking and apply it to an interface between a metal and (p-or n-type) semiconductor to make a metal-semiconductor heterojunction, what will the expected outcome be? Use diagrams and words to explain.

Question 6 a) Explain how the holes move in valence band to carry current.  b) At very high temperatures extrinsic semiconductors behave like intrinsic semiconductor. Explain this.

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.

When a pentavalent impurity is added to a pure semiconductor, it becomes O a. An insulator O b. p-type semiconductor O c. n-type semiconductor Od. An intrinsic semiconductor ject Jump to...

Consider the two devices shaun below which are fabricated from the semiconductor material. same i) ii) p-type metal n-tmpe Metal metel n-pe metal than ncident on b) if the metal contects across the device is connected with a wire, do you expect current flow hE any ii). in device i) and Explain in te werds each.

Q. Calculate the hole and electron densities in a N-type germaniumsemiconductor at room temperature. The conductivity of semiconductor bar is 500 S/cm. The mobility of electrons and holes at room temperature for germanium is 3800 cm2/ Vs and 1800 cm2/ Vs respectively and ni= 2.5 × 1013/cm3.

Compare the temperature dependence of the conductivity for metals and intrinsic semiconductors. Briefly explain the difference in behavior.

Subject - Semi Conductor's At 300K, fermi level is found to be 0.2eV below the edge of conduction band for an n-type silicon semiconductor. Find the electron and hole concentrations. After doping again, fermi level is now founded 0.25eV below the edge of conduction band. Find the type and concentration of impurity atoms added at the later stage At 300K, Nc= 2.8x 1019 cm3

What is the resistance in the forward-conduction region of the shockley diode based from the problem. No need to compute for the current.

Calculate the intrinsic carrier concentration of a semiconductor in units of (cm-3). Use the room temperature bandgap and effective density of states. Assume the parameters given below: Semiconductor: Germanium Temperature: 206 (K)

Problem 2. In a typical MOSFET structure with a p-Si body, the Drain/Body and Source/Body regions are comprised of pn- junction diodes because the Drain and Source electrodes are attached to the p-Si body layer through a small island-like region of n-Si. If these n-Si regions were not present, describe what would happen if you tried to measure the channel current between the Source and Drain electrodes in this device (assuming the gate voltage has properly created an inversion channel)?

Consider an extrinsic semiconductor. Given: /n = 6550 cm² /V sec Mp = 400 cm²/V sec ni = 5.6 x 1012/cm³ Find out the hole and electron concentration in the semiconductor when conductivity is minimum (in cm-³).

Intrinsic semiconductors are those in which the number of free carriers in the material is determined solely by temperature. In contrast, it is possible to produce extrinsic semiconductors by controlled insertion of impurities. Provide and explain at least two advantages of using the doping technique compared to using intrinsic materials.

As the forward current through a silicon diode increases, the voltage across the diode increases to a 0.7 V maximum. decreases and then increases. decreases. is relatively constant. A silicon diode in a half-wave rectifier has a barrier potential of 0.7 V. This has the effect of What is the order of doping, from heavily to lightly doped, for each region?

What is effective mass? Derive an expression for the effective mass in semiconductors. On an E-k plot, indicate heavy and light electrons and holes. Explain the meaning of negative effective mass.

Which of the following statements is false? A. We can create an extrinsic semiconductor materials by adding impurities to an intrinsic semiconductors. B. A pentavalent impurity addition to an intrinsic semiconductor gives N-type semiconductor. C. N-type semiconductor has more holes than the free electrons that contribute to the conduction of current. D. The P-type semiconductors have more holes than the free electrons.

Select ALL statements below that are TRUE.  A.   In p-type semiconductors, the dopant element typically contains three-valence electrons. B.  The critical temperature is the temperature above which the vapor cannot be solidified no matter the applied pressure. C.  In the band model, the electrons are assumed to occupy molecular orbitals. D.  Conduction bands are closely spaced molecular orbitals with filled electron spaces. E.   In the electron sea model, the valence electrons in metals are assumed to be fixed in the lattice points.

The carrier concentrations (Figure 1) are approximations for the case where the net (n-type or p-type) doping of the semiconductor is very well defined (>> ni ). For generic semiconductor doping, the relations in Figure 2 take effect. Deduce the relations from Figure 2. Please explain each step as I'm having trouble in understanding this subject. P.S.: I sent this question before and the signals in Nd and Na came out wrong. Please be aware!

(From the information given below for N and P type materials, .......... is/are correct. I- . (N-type material majority carrier is free electrons.) II- (P-type material minority carrier is holes.) III- (Phosphorus is not used to create a type N material for doping.) IV-  (Indium atoms can be found in the P-type crystal structure.)

Notes: Answer all questions With All Necessary Details. Q. 1: The e electrical resistance of a P- N crystal is very high at the reverse biasing, explain why. Q.2: Draw and describe the electric charge density graph through a P- N crystal. Q.3: Explain with drawing why the majorities in the N- type semiconductors are the free electrons. Q.4: Explain why the saturation current depends on temperature.

The maximum electric field in a reverse - biased semiconductor p - n junction at T - 300K is to be | Emax = 1 * 10% V / cm. the doping concentrations are Nv = 1 * 10 'cm and Nx = 2x10 cm. Determine the reverse - bias voltage (in volt) that will produce this maximum electric field. Where n = 2.1 x 10 cm and, es - 12.9.

In a semiconductor it is observed that 0.7 of the current is carried by holes and 0.3 by electrons. If the drift speed of the electrons is two times that of the holes, what is the ratio of electrons over holes?