(e) What is the conductivity of a silicon wafer at absolute \"K? Show calculatio
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(e) What is the conductivity of a silicon wafer at absolute "K? Show calculations and explain in detail for the answer. What is the resistivity of a silicon wafer at absolute 0°K? Show calculations and explain in detail for the answer. What is the Ro for the intrinsic Si of 1 mm thickness at absolute 0°K? (g) (h) What is the Ro for the intrinsic Si of 1 mm thickness at absolute 300°K? (i) What is the number of broken bonds in Si at 0 °K? C) What is the number of broken bonds in Si at 300 °K? (k) What is the hole density in Si at 0 °K? () What is the hole density in Si at 300 °K? (m) What is the electron density in Si at 0°K? (n) What is the electron density in Si at 300 °K? (p) Convert 10 micron (micro-meter) depletion thickness Xd to cm.Explanation / Answer
For an electron to move inside a valency band it needs thermal energy and this is provided by temperature. So as temperature increases the energy supplied to electron increases which in turn increases conductivity.
e) So at absolute zero of temperature the conductivity of a silicon wafer is zero.
f) When there is no energy supplied to a semiconductor it will be an insulator at 0k but when temperature increases conductivity increases and resistivity decreases. Resistivity formula () = 1/(conductivity).
g) & h) Resistance(R0) : first we find the mobility of the intrinsic silicon() = q (nn + pp) from this find and by substituting in R = l/A(1mm).
i) The bonds broken at 0k are zero because the wafer will be at equilibrium and number of holes = number of electrons and there is no energy supplied to break the bonds.
j) Broken bonds at room temp(300K) : broken bonds( ni = 1.5 x 1010 cm-3)/total possible bonds( 5 x 1022 Si atoms/cm3 x 4 bonds/atom)
k) & l) hole density in Si at temperature(T) : p = Nve-(EF-EV)/KT (T=0K and 300K)
m) & n) electron density in Si at temperature(T) : n = Nce-(EC-EF)/KT (T=0K and 300K)
p) 1m is 100cm so 10micron(10-5m) will be 100x10-5 = 10-3cm.
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