M.Sc. (Semester IV) (CBCS) Examination Mar/Apr-2018
Electronics
NANOELECTRONICS
Time: 2½ Hours
Max. Marks: 70
Instructions: Q. 1 and 2 are compulsory. Answer any three questions from Q.3 to Q.7 Answer any 5 questions. Figures to the right indicate full marks.
Q.1
Choose the alternatives given below.
08
The MBE technique is important for fabrication of DEG system.
2
1
0
3
The operation of negative differential resistor quantum well electron device is based on
quantum confined stark effect
resonant tunnel effect
both a b
none of these
The transistor based on hot electron is called transistor.
hot hole
hot
hot electron
electron
The triangular well wave functions are due to the asymmetry of the potential well.
neither symmetric or antisymmetric
symmetric
neither asymmetric or antisymmetric
antisymmetric
The SiGe heterojunctions have lattice constant difference between Si and Ge, which is about 4%.
small
large
equal
none of these
The superlattice consists of a set of Multiple Quantum Well (MQW).
periodic
regular
irregular
none of these
The OLED's are an electroluminescent organic material between two of different work functions.
semiconductors
nonconductors
insulator
conductors
The triangular well is effectively DES system.
zero
two
one
three
Page 2 of 2
SLR-UJ-345
State True or false.
06
The zero DEG structure is often called as artificial atoms.
The organic semiconductor has and σ bonds.
The homo-structures are made from the same material with non-uniform doping.
The motion of particle in the nanoworld is determined by wave and quantum mechanics.
If λ>Lx, Ly and Lx, Ly<<Lz then it stands for quantum well.
The particle moves throughout the structure without scattering is called diffusive regime of particle.
Q.2
Attempt any two of the following.
10
Explain the quantum well, wire and dots in brief considering the lengths.
Discuss advantages of the nanostructures.
Discuss in brief nanotechnology and nanoelectronics.
Explain the quantum dots with DOS diagram.
04
Q.3
What do you mean by MOSFET structures?
09
Write a note on quantum wire.
05
Q.4
Explain in detail Heterojunctions.
09
Write on nanoimprint lithography.
05
Q.5
Explain the parabolic and triangular quantum well.
09
Write a note on Coulomb Blockade.
05
Q.6
Explain the concept of superlattice and discuss the Kronig-Penney model of superlattice.
09
Write a note on any three characteristics length in nanostructures.
05
Q.7
Explain in detail tunneling effect and tunneling elements.
09
Write a note on OLED.
05