6. (14) A silicon wafer (Si: ni=10cm-3 and Er=11 ) is used to make a PN junction over a circular area with a diameter r=1mm.
6. (14) A silicon wafer (Si: ni=10cm-3 and Er=11 ) is used to make a PN...
1. Draw the schematics of forward-biased and negative-biased diodes. Show the polarity of voltage source (positive and negative terminal of the source), the position of Fermi levels and the current direction. Explain why there is a small current flow when a p-n junction is under reverse bias. 2. A p-n junction can be made by diffusing acceptor atoms into an n-type semiconductor. Suppose that boron is diffused into a silicon wafer doped with arsenic at 1015 cm-3 such that the...
Taking pure silicon (Si) as an example, explain what is meant by the terms electron-hole generation and recombination, how they affect the electrical conductivity, and define what is meant by the "intrinsic carrier density", n. [5 marks] Q3. a) b) With the aid of both lattice and energy band diagrams, explain how n-type doping of Si is achieved and state two types of suitable dopant atoms. [7 marks] c) An n-type region on a Si wafer has a donor concentration...
3. (40 pts) The capacitance of a silicon pn junction diode with an area 10° cm2 is measured. A plot of 1/C2 vs. the applied voltage Va is shown. The dashed line is extrapolated, continuing the data with a constant slope. From the junction capacitance formula and the dependence of W on Vbi-VA, one can obtain an equation for 1/C (a) If the diode is a one-sided junction, find the doping density on the low side from the measured (estimate...
3.13 Si pn junction Consider a long pn junction diode with an acceptor doping Naof 1018 cm-3 on the p-side and donor concentration of Nj on the n-side. The diode is forward biased and has a voltage of 0.6 V across it. The diode cross-sectional area is 1 mm2. The minority carrier recombination time, T, depends on the total dopant concentration, Ndopant (cm), through the following approximate empirical relation (5x 10-7)/(1 + 2 10-17N1°pan.) where T is in seconds. (a)...
3. A silicon step junction has uniform impurity doping concentrations of N. 5 x 1015 cm-3 and Nd = 1 x 1015 cm-, and a cross-sectional area of A-|0-4 cm2. Let tao -0.4 s and tpo 0.1 us. Consider the geometry in Figure.Calculate (a) the ideal reverse saturation current due to holes, (b) the ideal reverse saturation current due to electrons, (c) the hole concentration at a, if V V and (d) the electron current at x = x" +...
Problem 1 (25 points) Consider a silicon pn junction with a cross section area of 1x105 cm, a forward bias Va 0.5V, and the following parameters at T- 300K: 16cm-3 15 3 -6 KT n: 1.5x100 cm", ε' = 1 1 .7x 8.854x 10-14 Flon;ー-0.025 V Assume the critical field to be equal to 3x105 V/cm. a) (5 points) Compare the hole density at xn to the electron density at-Xp b) (5 points) Compare the hole current at xn to...
1) Useful parameters for CdTe a. ni- 1e8 cm 3 2) kT 25.8mev Problem #1 (100 points) Consider an ideal, long-diode type solar cell made of a CdTe abrupt asymmetrical PN junction. The relevant properties of the p-type CdTe absorber are: thickness - 3 um, doping - le14 cm3, electron mobility 100 cm2/V/s, and electron lifetime 10 ns. The n type region is doped much higher than CdTe 1. Calculate the saturation current density 2. Calculate the short-circuit current, assuming...
EENG 245 Physical electronics HW 1 1) The NaCl crystal is cubic, and can be described as follows. Na atoms sit at the corners and faces of a cube, and Cl atoms sit in between two Na atoms. This means that a Clatom is found half-way along each of the cube edges, and there is a Cl in the center of the cube. (We could also have described the lattice by interchanging Na and Cl in the description above.) Another...