Optical Processes in Semiconductors: Review A. Aydınlı
Dec 21, 2015
Optical Processes in Semiconductors: Review
A. Aydınlı
PL Emission of optical radiation
resulting from excitation to a nonequilibrium state by irradiation with light. Create electron-hole pairs by
absorption of exciting light Radiative recombination of electron-
hole pairs Escape of recombination radiation from
the sample.
PL
Sensitive (compared to absorption) Nondestructive Simple to perform Considerable analysis may be
required to reach the physical mechanism
Electron-Photon Interaction
Solve:
To obtain:
)()(2
1 2
0
rVeApm
H
0
22
00
2
2)(
2)(
2 m
AepAAp
m
erV
m
pH
)()(2 2'
ababs EEarHbW
pAm
eH
0
')(
2 0
2
rVm
pH
Fermi’s Golden Rule Interaction energy between the radiation field
and atomic system can be written either
222 )2/()/( jj
j AmcepAmceH
jj reEHor
Absorption/Emission
DOS
Transitions in Bulk
Emission vs Gain
Direct Gap Absorption
Direct Gap Absorption
Absorption in QW
Population Inversion in a QW
Intersubband Absorption
Intersubband Absorption
Inter- and intraimpurity Transitions
Free-bound:
Band-band:
Degeneracy: