Electrical properties of Gallium Arsenide (GaAs)
Electrical properties
Basic ParametersMobility and Hall Effect
Transport Properties in High Electric Fields
Impact Ionization
Recombination Parameters
Basic Parameters
Breakdown field  ≈4·10^{5} V/cm 
Mobility electrons  ≤8500 cm^{2} V^{1}s^{1} 
Mobility holes  ≤400 cm^{2} V^{1}s^{1} 
Diffusion coefficient electrons  ≤200 cm^{2}/s 
Diffusion coefficient holes  ≤10 cm^{2}/s 
Electron thermal velocity  4.4·10^{5} m/s 
Hole thermal velocity  1.8·10^{5}m/s 
Mobility and Hall Effect
Electron Hall mobility versus temperature for different doping levels. (Stillman et al. [1970] 1. Bottom curve: N_{d}=5·10^{15}cm^{3}; 2. Middle curve : N_{d}=10^{15}cm^{3}; 3. Top curve : N_{d}=5·10^{15}cm^{3} For weakly doped GaAs at temperature close to 300 K, electron Hall mobility µ_{H}=9400(300/T) cm^{2} V^{1} s^{1} 

Electron Hall mobility versus temperature for different doping levels and degrees of compensation (high temperatures): Open circles: N_{d}=4N_{a}=1.2·10^{17} cm^{3}; Open squares: N_{d}=4N_{a}=10^{16} cm^{3}; Open triangles: N_{d}=3N_{a}=2·10^{15} cm^{3}; Solid curve represents the calculation for pure GaAs (Blakemore[1982]). For weakly doped GaAs at temperature close to 300 K, electron drift mobility µ_{n}=8000(300/T)^{2/3} cm^{2} V^{1} s^{1} 

Drift and Hall mobility versus electron concentration for different degrees of compensation T= 77 K (Rode [1975]). 

Drift and Hall mobility versus electron concentration for different degrees of compensation T= 300 K (Rode [1975]). 
Approximate formula for the Hall mobility
. µ_{n }=µ_{OH}/(1+N_{d}·10^{17})^{1/2}, where µ_{OH}≈9400 (cm^{2} V^{1} s^{1}), N_{d} in cm^{3}(Hilsum [1974]).
Temperature dependence of the Hall factor for pure ntype GaAs in a weak magnetic field (Rode [1975]). 

Temperature dependence of the Hall mobility for three highpurity samples (Wiley [1975]) 
For GaAs at temperatures close to 300 K, hole Hall mobility
(cm^{2}V^{1}s^{1}), (p  in cm^{3)}For weakly doped GaAs at temperature close to 300 K, Hall mobility
µ_{pH}=400(300/T)^{2.3} (cm^{2} V^{1} s^{1}).
The hole Hall mobility versus hole density. (Wiley [1975]) 
At T= 300 K, the Hall factor in pure GaAs
r_{H}=1.25.Transport Properties in High Electric Fields
Field dependences of the electron drift velocity. (Blakemore[1982]). Solid curve was calculated by (Pozhela and Reklaitis[1980]). Dashed and dotted curves are measured data, 300 K 

Field dependences of the electron drift velocity for high electric fields, 300 K. (Blakemore[1982]). 

Field dependences of the electron drift velocity at different temperatures. (Pozhela and Reklaitis[1980]). 

Fraction of electrons in L and X valleys. n_{L} and n_{X} as a function of electric field F at 77, 160, and 300 K, N_{d}=0 (Pozhela and Reklaitis[1980]). Dotted curve  L valleys, dashed curve  X valleys. 

Mean energy E in Γ, L, and X valleys as a function of electric field F at 77, 160, and 300 K, N_{d}=0 (Pozhela and Reklaitis[1980]). Solid curve  Γ valleys, dotted curve  L valleys, dashed curve  X valleys. 

Frequency dependences of electron differential mobility. µ_{d} is real part of the differential mobility; µ_{d}^{*}is imaginary part of differential mobility. F= 5.5 kV cm^{1} (Rees[1969]). 

The field dependence of longitudinal electron diffusion coefficient DF. Solid curves 1 and 2 are theoretical calculations. Dashed curves 3, 4, and 5 are experimental data. Curve 1  from (Pozhela and Reklaitis[1980]). Curve 2  from (Fauquembergue et al.[1980]). Curve 3  from (Ruch and Kino[1968]). Curve 4  from (Bareikis et al.[1978]). Curve 5  (from de Murcia[1991]). 

Field dependences of the hole drift velocity at different temperatures. (Datal et al. [1971]). 

Temperature dependence of the saturation hole velocity in high electric fields (Datal et al. [1971]). 

The field dependence of the hole diffusion coefficient. (Joshi and Crendin [1989]). 
Impact Ionization
There are two schools of thought regarding the impact ionization in GaAs.
The first one states that impact ionization rates α_{i} and β_{i} for electrons and holes in GaAs are known accurately enough to distinguish such subtle details such as the anisothropy of α_{i} and β_{i} for different crystallographic directions. This approach is described in detail in the work by Dmitriev et al.[1987].
Experimental curves α_{i} and β_{i} versus 1/F for GaAs. (Pearsall et al. [1978]). 

Experimental curves α_{i} and β_{i} versus 1/F for GaAs. (Pearsall et al. [1978]). 

Experimental curves α_{i} and β_{i} versus 1/F for GaAs. (Pearsall et al. [1978]). 
α_{i} = β _{i }=α_{o}exp[δ  (δ^{2} + (F_{0 }/ F)^{2})^{1/2}]
where α_{o} = 0.245·10^{6} cm^{1}; β = 57.6 F_{o} = 6.65·10^{6} V cm^{1} (Kyuregyan and Yurkov [1989]).
Breakdown voltage and breakdown field versus doping density for an abrupt pn junction. (Kyuregyan and Yurkov [1989]). 
Recombination Parameter
Pure ntype material (n_{o} ~ 10^{14}cm^{3})  
The longest lifetime of holes  τ_{p} ~3·10^{6} s 
Diffusion length L_{p} = (D_{p}·τ_{p})^{1/2}  L_{p} ~3050 µm. 
Pure ptype material  
(a)Low injection level  
The longest lifetime of electrons  τ_{n} ~ 5·10^{9} s 
Diffusion length L_{n} = (D_{n}·τ_{ n})^{1/2}  L_{n} ~10 µm 
(b) High injection level (filled traps)  
The longest lifetime of electrons  τ ~2.5·10^{7} s 
Diffusion length L_{n}  L_{n} ~ 70 µm 
Surface recombination velocity versus doping density (Aspnes [1983]). Different experimental points correspond to different surface treatment methods. 
Radiative recombination coefficient (Varshni[1967])
90 K  1.8·10^{8}cm^{3}/s 
185 K  1.9·10^{9}cm^{3}/s 
300 K  7.2·10^{10}cm^{3}/s 
Auger coefficient
300 K  ~10^{30}cm^{6}/s 
500 K  ~10^{29}cm^{6}/s 