Chapter 40.8, Problem 1GE

In an unbiased p-n junction, holes diffuse from the p-region to n-region because(a) free electrons in the n-region attract them.(b) they move across the junction by the potential difference.(c) hole concentration in p-region is more as compared to n-region.(d) All the above

The figure shows the pn junction 250 micrometers long and made of silicon with a surface area of ​​100 micrometers square. In this pn junction, the I region is doped with 10 ^ 19 cm ^ -3 and in the II: region with 10 ^ 17 cm ^ -3 atoms. Only when the S1 switch is closed, the maximum is drawn from the "a-b" ends and 250 mA flows from the circuit. The ability of electrons to move in the pn junction is 1200 cm ^ 2 / V.s, and the ability of the holes to move is 400 cm ^ 2 / V.s. What is the channel width accordingly? (W =?)

In the fabrication of a p-type semiconductor, elemental boron is diffused a small distance into a solid crystalline silicon wafer. The boron concentration within the solid silicon determines semiconducting properties of the material. A physical vapor deposition process keeps the concentration of elemental boron at the surface of the wafer equal to 5.0 x 1020 atoms boron/cm3 silicon. In the manufacture of a transistor, it is desired to produce a thin film of silicon doped to a boron concentration of at least 1.7 x 1019 atoms boron/cm3 silicon at a depth of 0.20 microns (µm) from the surface of the silicon wafer. It is desired to achieve this target within a 30-min processing time. The density of solid silicon can be stated as 5.0 x 1022 atoms Si/ cm3 solid. (a) At what temperature must the boron-doping process be operated? It is known that the temperature dependence of the diffusion coefficient of boron (A) in silicon (B) is given by Where Do=0.019 cm2/s and Qo=2.74 x 105…

Q 2/ If the electron density of a pure semiconductor at a temperature of 17 C is m3/1016, and when the temperature increases by ten times, the electron density becomes m3/1019. If impurities of arsenic are added to one end of this material, the concentration of the majority charge carriers becomes m3/1023, and impurities of boron are added to the other end, so that the concentration of the majority charge carriers becomes m3/1021, thus forming a p-n junction with a contact area of 10-7 m2. Calculate what I am at 17.C 1- Fermi position at each end 2- Energy gap in ev 3- The ratio of the current of holes to the current of electrons through the junction if you know that the mobility of electrons is m/Vs 0.5 and the mobility of holes is m/Vs 0.25 and the length of the minority electrons is 0.4 mm and the length of the minority holes is 0.3 mm 4- Density of carriers for each party (majority and minority) 5- The effort of the divider 6- The junction current at an amplitude of 0.4 7- The…

A PN junction in series with a resistor of 100N and current of 100mA flows. If the voltage cross the junction is reversed instantaneously to 10V at t= 0, the reverse current that flows through the diode is a) 50 mA b) 75 mA c) 100 mA d) 200 mA

Example 1: Find the hole concentration in N-type semiconductor when the donor concentration is 2 x102cm-3 and intrinsic value of silicon material at T = 300° K is 1.25 x10 cm-3. ст %3D ст

(a) Calculate the thermal-equilibrium electron concentration in silicon at T = 300 K for the case when EF = E.. (b) Calculate the thermal-equilibrium hole concentration in silicon at T = 300 K for the case when EF= E. %3D 61 [Ans. (a) no = 2.05 × 1019 cm-3; (b) po = 7.63 x 1018 cm-3]

In a p-type semiconductor with a defect-rich surface the surface recombination velocity is 104 cm/s. (i) draw a schematic figure illustrating how the surface recombination flux changes with input light intensity; (ii) How does the surface recombination flux change with doping level?

what would happen if we replaced the PVC rod with a semiconductor material? What mechanisms could we employ to inject energy into the bound charges in the semiconductor to force it to act like more of a conductor?