Optical properties of Gallium Arsenide (GaAs)

GaAs - Gallium Arsenide

Optical properties

Infrared refractive index 3.3
Radiative recombination coefficient 7·10-10 cm3/s

Infrared refractive index

n = k1/2 = 3.255·(1 + 4.5·10-5T)
for 300 K n= 3.299

Long-wave TO phonon energy

TO = 33.81·(1 - 5.5·10-5 T) (meV)
for 300 KTO = 33.2 meV

Long-wave LO phonon energy

LO= 36.57·(1 - 4·10-5 T) (meV)
for 300 K LO = 36.1 meV
Refractive index n versus photon energy for a high-purity GaAs.(no~5·1013 cm-3).
Solid curve is deduced from two-beam reflectance measurements at 279 K. Dark circles are obtained from refraction measurements. Light circles are calculated from Kramers-Kronig analysis
(Blakemore [1982]).
Normal incidence reflectivity versus photon energy.
(Phillip and Ehrenreich [1963]).
Intrinsic absorption coefficient near the intrinsic absorption edge for different temperatures.
(Sturge [1962]).
A ground state Rydberg energy RX1= 4.2 meV
Intrinsic absorption edge at 297 K at different doping levels. n-type doping
(Casey et al. [1975]).
Intrinsic absorption edge at 297 K at different doping levels. p-type doping
(Casey et al. [1975]).
The absorption coefficient versus photon energy from intrinsic edge to 25 eV.
(Casey et al. [1975]).
Free carrier absorption versus wavelength at different doping levels, 296 K
(Spitzer and Whelan [1959]).
Conduction electron concentrations are:
1. 1.3·1017cm-3; 2. 4.9·1017cm-3; 3. 1018cm-3; 4. 5.4·1018cm-3
Free carrier absorption versus wavelength at different temperatures.
no = 4.9·1017cm-3 (Spitzer and Whelan [1959])
Temperatures are: 1. 100 K; 2. 297 K; 3. 443 K.

At 300 K

For λ~2 µm α=6·10-18 no (cm-1)  (no - in cm-1)
For λ > 4µm and 1017<no<1018cm-3α ≈ 7.5·10-20no·λ3 (cm-1)  (no - in cm-3, λ- µm)