Recent questions tagged intrinsic-and-extrinsic-semiconductor

Selenium (Se) is a group VI element (i.e. two columns to the right of Silicon on the periodic table). An extrinsic semiconductor is produced by doping Silicon (Si) with 1020 Selenium atoms per m3. Assuming saturation, calculate the conductivity of the extrinsic semiconductor.

asked Jul 13, 2014 by balaji.thirumalai

1 answer

Given $n_i = 2.4 \times 10^{19} m^{-3}, \; \mu_n = 0.39\;m^2/V.S, \; \mu_p = 0.19\;m^2/V.s$ for intrinsic Ge at room temperature of $300^{\circ}\;K$, calculate the conductivity of the sample.

asked Jul 13, 2014 by balaji.thirumalai

1 answer

Estimate the conductivity ($\sigma_i$) and resistivity ($\rho_i$) of silicon atoms and electron-hole pairs at room temperature of $300^{\circ}\;K$ if every 10-millionth silicon atom is replaced by an atom of Indium.

asked Jul 13, 2014 by balaji.thirumalai

1 answer

Estimate the intrinsic conductivity ($\sigma_i$) and resistivity ($\rho_i$) of silicon atoms and electron-hole pairs at room temperature of $300^{\circ}\;K$.

asked Jul 13, 2014 by balaji.thirumalai

1 answer

C, Si and Ge atoms have 4 Valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by $E_C, E_{Si}, E_{Ge}$ respectively. Which of the following relationship is true in their case?

asked Jul 13, 2014 by balaji.thirumalai

1 answer

Which of the following statements about intrinsic semiconductors are incorrect?

asked Jul 13, 2014 by balaji.thirumalai

1 answer

Suppose a pure Si crystal has $5 \times 10^{28} \text{atoms} / m^3$. It is doped by 1 ppm concentration of pentavalent As. Calculate the number of electrons and holes, given that $n_i = 1.5 \times 10^{16} \;/m^3$

asked Jul 13, 2014 by balaji.thirumalai

1 answer

A semiconductor has an electron concentration of $0.45 \times 10^{22} \; /m^3$ and a hole concentration of $5 \times 10^{20} \;/ m^3$. Find its conductivity.

asked Jul 13, 2014 by balaji.thirumalai

1 answer

A p type semiconductor has acceptor level of 57 mev above the valance band. Find the maximum wave length of light which can create a hole.

asked Jul 13, 2014 by balaji.thirumalai

1 answer

An electron enters the p-n junction from the n-side with a velocity of $5 \times 10^5 m/s$ . If the depletion region is $5 \times 10^{-7} m/s$ wide and the potential barrier is $0.5 V$ What will be its speed When it enters P side ?

asked Jan 28, 2014 by meena.p

1 answer

An electron losely bound to the impurity of a doped semiconductor is able to jump to the conducting band because of thermal collision at temperature T k. If the impurity level is 15 mev below the conducting band, calculate the temperature.

asked Jan 28, 2014 by meena.p

1 answer

What is the resistivity of n-type semiconductors given: Density of conducting electrons $=8 \times 10^{13} /cc$; Density of holes $=5 \times 10^{12} /cc$ mobility of electron $=2.3 \times 10^4 cm^2 /v-s$ mobility of holes $=100 cm^2 /v-s$

asked Jan 28, 2014 by meena.p

1 answer

In Germanium it is found that concentration of conducting electron is $3 \times 10^{19} $ per cubic meter. When Phosphorus impurity is doped the concentration of conducting electron increases to $2 \times 10^{23}$ per cubic meter. If product of hole concentration and conducting electron is independent of amount of impurity find the hole concentration in doped Germanium.

asked Jan 27, 2014 by meena.p

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In pure semiconductor number of conducting electrons is $5 \times 10^{20} $ per cubic meter. How many holes are there in $1 cm^3$ of the same semiconductor.

asked Jan 27, 2014 by meena.p

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What is intensity of electric field in the depletion region of which $2.5 \times 10^{-7} m$ if the potential barrier is $0.50 v$

asked Jan 27, 2014 by meena.p

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A p type semiconductor has acceptor level of 50 mev above the valance band. Find the maximum wave length of light which can create a hole.

asked Jan 27, 2014 by meena.p

1 answer

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