Chapter 15: Display Devices

Example 15.1, page no-406

In [2]:
# wavelength of light

import math
#Variable Declaration
e=1.609*10**-19           # Charge of electron
eg=1.8                    # energy band gap
E=e*eg                    
h=6.626*10**-34           # Planck's constant
c=3*10**8                 # speed of light

#Calculation
lam=h*c/E

#Result
print('The wavelenth of light emitted from given LED is %.4f µm'%(lam*10**6))

The wavelenth of light emitted from given LED is 0.6863 µm

Example 15.2, page no-406

In [3]:
# Band Gap of GaAsP

import math
#Variable Declaration
e=1.6*10**-19             # Charge of electron
h=6.626*10**-34           # planck's constant
c=3*10**8                 # speed of light in m/s
lam=6751*10**-10          # wavelength of green light from mercury lamp

#Calculation
E=h*c/lam
E=E/e

#Result
print('The band gap of the given GaAsP is %.1f eV'%E)

The band gap of the given GaAsP is 1.8 eV