1
GATE ECE 2014 Set 4
Numerical
+2
-0
Consider a silicon sample doped with ND = 1×1015/cm3 donor atoms. Assume that the
intrinsic carrier concentration ni = 1.5×1010/cm3. If the sample is additionally doped with NA = 1×1018/cm3 acceptor atoms, the approximate number of electrons/cm3 in the sample, at
T=300 K, will be _________________.
Your input ____
2
GATE ECE 2014 Set 4
MCQ (Single Correct Answer)
+2
-0.6
An N-type semiconductor having uniform doping is biased as shown in the figure.
If EC is the lowest energy level of the conduction band, EV is the highest energy level of the valance band and EF is the Fermi level, which one of the following represents the energy band diagram for the biased N-type semiconductor?
3
GATE ECE 2014 Set 2
Numerical
+2
-0
Assume electronic charge q = 1.6×10-19 C, kT/q = 25 mV and electron mobility μn = 1000
cm2/V-s. If the concentration gradient of electrons injected into a P-type silicon sample is
1×1021/cm4, the magnitude of electron diffusion current density (in A/cm2) is _________.
Your input ____
4
GATE ECE 2010
MCQ (Single Correct Answer)
+2
-0.6
The silicon sample with unit cross-sectional area shown below is in thermal
equilibrium. The following information is given: T=300K, electronic charge=1.6x10-
19C, thermal voltage=26mV and electron mobility = 1350cm2/V-s
The magnitude of the electron drift current density at x=0.5 μm is
Questions Asked from Semiconductor Physics (Marks 2)
Number in Brackets after Paper Indicates No. of Questions
GATE ECE Subjects
Network Theory
Control Systems
Electronic Devices and VLSI
Analog Circuits
Digital Circuits
Microprocessors
Signals and Systems
Representation of Continuous Time Signal Fourier Series Discrete Time Signal Fourier Series Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Transmission of Signal Through Continuous Time LTI Systems Discrete Time Linear Time Invariant Systems Sampling Continuous Time Signal Laplace Transform Discrete Fourier Transform and Fast Fourier Transform Transmission of Signal Through Discrete Time Lti Systems Miscellaneous Fourier Transform
Communications
Electromagnetics
General Aptitude