## Electrical properties

Basic Parameters
Mobility and Hall Effect
Transport Properties in High Electric Fields
Impact Ionization
Recombination Parameters

### Basic Parameters

 Breakdown field ≈4·104 V cm-1 Mobility of electrons ≤4·104 cm2V-1s-1 Mobility of holes ≤5·102 cm2 V-1s-1 Diffusion coefficient of electrons ≤103 cm2s-1 Diffusion coefficient of holes ≤13 cm2 s-1 Electron thermal velocity 7.7·105 m s-1 Hole thermal velocity 2·105 m s-1

### Mobility and Hall Effect

Electron Hall mobility versus temperature for different electron concentration:
full triangles no= 4·1015 cm-3,
circles no= 4·1016cm-3,
open triangles no= 1.7·1016cm-3.
Solid curve-calculation for pure InAs.
(Rode [1975])
Electron Hall mobility versus electron concentration. T = 77 K.
(Karataev et al. [1977]).
Electron Hall mobility versus electron concentration T = 300 K
(Karataev et al. [1977]).
Electron Hall mobility (R·σ) in compensated material
 Curve n cm-3 Na+Nd cm-3 θ=Na/Nd 1 8.2·1016 3·1017 0.58 2 3.2·1017 6.1·1018 0.9 3 5.1·1016 3.2·1018 0.96 4 3.3·1016 7.5·1017 0.91 5 7.6·1015 3.4·1017 0.95 6 6.4·1015 3.8·1017 0.96 7 3.3·1015 3.9·1017 0.98
(Garyagdyev et al. [1974]).
Electron Hall mobility versus transverse magnetic field, T = 77 K.
Nd (cm-3):
1. 1.7·1016;
2. 5.8·1016.
(Kamakura et al. [1975]).
At T = 300 K the electron Hall factor in pure n-InAs rH ~1.3.
 Hole Hall mobility (R·σ) versus temperature for different acceptor densities. Hole concentration at 300 K po (cm-3): 1. 5.7·1016; 2. 2.6·1017; 3. 4.2·1017; 4. 1.3·1018. (Kasamanly et al. [1968]). Hall coefficient versus temperature for different acceptor densities. Hole concentration at 300 K po (cm-3): 1. 5.7·1016; 2. 2.6·1017; 3. 4.2·1017; 4. 1.3·1018. (Kasamanly et al. [1968]).

### Transport Properties in High Electric Fields

 Steady state field dependence of the electron drift velocity, 300 K, F || (100). Theoretical calculation (Brennan and Hess[1984]). Field dependence of the electron drift velocity at different transverse magnetic fields for long (microsecond) pulses. Experimental results, 77 K Magnetic field B(T): 1. 0.0; 2. 0.3; 3. 0.9; 4. 1.5. (Kamakura et al. [1975]). Field dependence of the electron drift velocity, 77 K. Solid lines show results of theoretical calculation for different non-parabolicity α (eV-1): 1. 2.85; 2. 2.0; 3. 1.5. (Kuchar et al. [1973]). Points show experimental results for very short (pico-second pulses) (Krotkus and Dobrovolskis[1988]).

### Impact Ionization

 The dependence of ionization rates for electrons αi and holes βi versus 1/F, T =77K (Mikhailova et al. [1976]).

#### For electrons:

αi = αoexp(-Fno/ F)
αo = 1.8·105 cm-1;
Fno = 1.6·105 V cm-1 (77 K)

#### For holes:

βi = βoexp(-Fpo/ F)
At 77 K
 1.5·104 V cm-1 < F < 3·104 V cm-1 3·104 V cm-1 < F < 6·104 V cm-1 βo = 4.7·105 cm-1; βo = 4.5·106 cm-1; Fpo = 0.85·105 V cm-1. Fpo = 1.54·105 V cm-1
 Generation rate g versus electric field for relatively low fields, T = 77 K. Solid line shows result of calculation. Experimental results: open and full circles -undoped InAs, open triangles - compensated InAs. (Krotkus and Dobrovolskis[1988]). Breakdown voltage and breakdown field versus doping density for an abrupt p-n junction, 77 K.

### Recombination Parameters

 Pure n-type material (no =2·10-15cm-3) The longest lifetime of holes τp ~ 3·10-6 s Diffusion length Lp Lp ~ 10 - 20 µm. Pure p-type material The longest lifetime of electrons τn ~ 3·10-8 s Diffusion length Ln Ln ~ 30 - 60 µm
Characteristic surface recombination rates (cm s-1) 102 - 104.