2E8 - Tutorials 2
Optical Properties and Semiconductors 1
1. Illustrative Problem
If a wave with a wavelength of 14 cm is traveling at a velocity of 34 m/s, what is the wave’s
frequency?
2. Illustrative Problem
Calculate the wavelength of a 60 Hz electromagnetic wave.
3. Illustrative Problem
Find the speed of yellow light with a wavelength of 589 nm travels through diamond. Diamond’s
index of refraction is 2.42.
4. Illustrative Problem
Name the 4 processes that occur when light strike the surface of a solid material.
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5. Illustrative Problem
List a few laser applications.
6. Illustrative Problem
What is the initial process which must occur before the emission of the laser light? What are the
main properties of the laser light? What lasing materials have already been discovered?
7. Illustrative Problem
List three optical classifications of materials.
8. Illustrative Problem
What is the photoelectric effect (and what are the photoelectrons)? From which consideration of
the light’s nature (wave nature or light phonons) can this phenomenon be explained?
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Semiconductor materials - I
1. Is the energy band of a donor atom near the valance energy band or conduction band?
2. What are the charge carriers for intrinsic semiconductors and for p-type and n-type
extrinsic semiconductors?
3. How many electrons does a Silicon atom have in its outer shell?
4. What is the ratio between electron-hole pair’s generation and recombination?
5. What is the type of crystalline structure and chemical bonding found in Silicon and
Germanium crystalline materials?
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DATA SHEET:
Free electron rest mass mo
Boltzmann’s constant k
9.11xl0-31kg
1.38 x 10-23 J/oK = 8.618x10-5 eV/K
Planck’s constant h
6.63x10-34 J s
Electronic charge q
Intrinsic carrier concentration of Si ni
1.6 x 10-19 C
1.5 x 1010 cm-3
Room temperature value of kT
0.0259 eV
Energy band gap Eg of Si
1.1 eV
Permittivity of vacuum  0
8.85 x 10-14F/cm
Reduced Planck’s constant
  h / 2
Speed of light
3 x 108 m/s
ΔT=1 oC = 1 K = 1.8°F; 1W = 3.41214 BTU/h; 1 ft = 0.3048 m; 1 ft = 12 in
mn* q 4
Eb 
2 K 22
;
K  40 r ;
f ( E F )  1  exp ( E F  E F ) / kT 
1
N c  2(
2mn* kT 3 / 2
)
h2
;
𝜎 = 𝑛𝑖 𝑞(𝜇𝑛 + 𝜇𝑝 );
 t   t  l0
;
;
2m *p kT
h2
1
1  exp ( E  E F ) / kT 

;
n0 
;
  1/ 
)3/ 2
p0  N v exp  ( EF  Ev ) / kT  ; ni  N c N v e  Eg / 2 kT
k
𝜎 = 𝜎0 exp⁡(−
;
q d

A t
t 
;
 f ( E ) N ( E )dE
Ec
n0  ni exp ( EF  Ei ) / kT  ;
;
C  k 0 A / d
1
1


11 2
N v  2(
n0  N c exp  ( Ec  EF ) / kT 
n 0 p0  ni2
f (E) 
𝐸𝑔
2𝐾𝑇
l
 t
l0
p0  ni exp ( Ei  E F ) / kT  ;
); 𝜎𝑛 = 𝑛0 𝑞𝜇𝑛 ; 𝜎𝑝 = 𝑝0 𝑞𝜇𝑝 ;
;
F  I  l  B  Sin ;
R
l
A
;
n c/v;
vl f
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