# Chapter 07 - OPTOELECTRONIC DEVICES¶

## Example E01 - Pg 352¶

In [1]:
# Exa 7.1 - 352
# Given data
O_V = 5.;# output voltage in V
V_D = 1.5;#voltage drop in V
R = (O_V - V_D)/O_V;
R = R * 10.**3.;# in ohm
print '%s %.2f' %("The resistance value in ohm is",R);
print '%s' %("As this is not standard value, use R=680 ohm which is a standard value")

The resistance value in ohm is 700.00
As this is not standard value, use R=680 ohm which is a standard value


## Example E02 - Pg 376¶

In [2]:
# Exa 7.2 - 376
# Given data
import math
N_A = 7.5*10.**24.;# in atoms/m**3
N_D = 1.5*10.**22.;# in atoms/m**3
D_e = 25.*10.**-4.;# in m**2/s
D_h = 1.*10.**-3.;# in m**2/s
Torque_eo = 500.;# in ns
Torque_ho = 100.;# in ns
n_i = 1.5*10.**16.;# in /m**3
e = 1.6*10.**-19.;# in C
P_C = 12.5;# in mA/cm**2
# Electron diffusion length
L_e = math.sqrt(D_e*Torque_ho*10.**-9.);# in m
L_e = L_e * 10.**6.;# in um
# hole diffusion length
L_h = math.sqrt(D_h*Torque_ho*10.**-9.);# in m
L_h = L_h * 10.**6.;# in um
# The value of J_s can be calculated as,
J_s = e*((n_i)**2.)*( (D_e/(L_e*10.**-6.*N_A)) + (D_h/(L_h*10.**-6.*N_D)) );# in A/m**2
J_s = J_s * 10.**3.;# in A/cm**2
V_T = 26.;# in mV
I_lembda = 12.5*10.**-3.;
I_s = 2.4*10.**-4.;
# Open circuit voltage
V_OC = V_T*math.log( 1.+(I_lembda/J_s) );# in mV
V_OC = V_OC * 10.**-3.;# in V
print '%s %.3f' %("Open circuit voltage in V is",V_OC);

# Note: There is calculation error to evaluate the value of VOC since 26*10**-3*log(1+12.5*10**-3/2.4*10**-4) calculated as 0.10318 not 0.522 V

Open circuit voltage in V is 0.103


## Example E03 - Pg 376¶

In [3]:
# Exa 7.3 - 376
# Given data
import math
Phi_o = 1.*10.**21.;# in m**-2s**-1
Alpha = 1.*10.**5.;# in m**-1
W = 25.;# in um
W =W * 10.**-6.;# in m
e = 1.6*10.**-19.;# in C
# At the front edge of intrinsic region, the generation rate of EHP
G_L1 = Alpha*Phi_o;# in m**-3s**-1
# At the back edge of intrinsic region, the generation rate of EHP
G_L2 = Alpha*Phi_o*math.e**( (-Alpha*W) );# in m**-3s**-1
# Photo current density,
J_L = e*Phi_o*(1-math.e**(-Alpha*W));# in A/m**2
J_L = J_L * 10.**-1.;# in mA/cm**2
print '%s %.2f' %("Photo current density in mA/cm**2 is",J_L);

Photo current density in mA/cm**2 is 14.69