The energy bandgap for lightly doped GaAs at

room temperature is 1.43 ev. When the material is

heavily doped , it is found that the lasing

transitions involve “ bandtail states”

Which effectively reduce the bandgap transition

by 8%. Determine the difference in emission

wavelength of the light between the lightly doped &

the heavily doped case.

k=1.38 *10-23 ; h =6.626 * 10-34 J.s​