Electrical properties of Gallium Phosphide (GaP)
Electrical properties
Basic ParametersMobility and Hall Effect Transport Properties in High Electric Fields
Impact Ionization
Recombination Parameters
Basic Parameters
| Breakdown field | ≈1·106 V/cm |
| Mobility electrons | ≤250 cm2 V-1s-1 |
| Mobility holes | ≤150 cm2 V-1s-1 |
| Diffusion coefficient electrons | ≤6.5 cm2/s |
| Diffusion coefficient holes | ≤4 cm2/s |
| Electron thermal velocity | 2·105 m/s |
| Hole thermal velocity | 1.3·105m/s |
Mobility and Hall Effect
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Electron Hall mobility versus temperature for different donor (Sn) densities. Nd (cm-3): 1. 5·1016; 2. 2·1017; 3. 2.5·1018; 4. 7.5·1018; 5. 1.2·1019. (Kao and Eknoyan [1983]). |
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Electron Hall mobility versus donor (Sn) density at different temperature. T (K): 1. 203; 2. 233; 3. 273; 4. 300; 5. 400; 6. 500. For T>200 K electron Hall mobility µnH~T-1.7 (Kao and Eknoyan [1983]). |
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Electron Hall mobility versus temperature for different acceptor (Zn) densities. Na (cm-3): 1. 6.7·1016; 2. 1.9·1017; 3. 6.7·1017; 4. 3.8·1018; 5. 1.2·1019. (Casey et al. [1969]). |
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Hole Hall mobility versus temperature for different acceptor (Mg) densities. Na (cm-3): 1. 5·1016; 2. 3·1017; 3. 6·1017; 4. 1·1018; 5. 2·1018. (Kao and Eknoyan [1983]). |
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Hole Hall mobility versus acceptor (Mg) density at different temperature. T (K): 1. 203; 2. 233; 3. 300; 4. 350; 5. 400; 6. 500. For T>200 K hole Hall mobility µpH~T-2.3 (Kao and Eknoyan [1983]). |
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Hole concentration versus temperature for different acceptor (Zn) densities. Na (cm-3): 1. 6.7·1016; 2. 6.7·1017; 3. 3.8·1018; 4. 1.2·1019; 5. 2.1·1019. (Casey et al. [1969]). |
Transport Properties in High Electric Fields
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Field dependences of the electron drift velocity 300 K. Solid line shows the result of the calculation. Dashed line shows the experimental results (Arora et al. [1987]). |
Saturation electron drift velocity
vs = 1.25·107 cm/s (300 K)(Johnson and Eknoyan [1985])
Impact Ionization
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The dependence of ionization rates for electrons αi and holes βi
versus electric field, 300 K. αi= βi (Sze [1969]). |
αi = β i = αo·exp(δ - (δ2 + (Fo/F)2)1/2,
where αo = 0.39·106 cm-1, δ=19.1, Fo=7.51·106 V cm-1
(Kyuregyan and Yurkov [1989]).
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Breakdown voltage and breakdown field versus doping density for an abrupt p-n junction, 300 K (Sze and Fibbons [1966]). |
Recombination Parameters
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Hole diffusion length Lp in n-type GaP (undoped or doped with S) versus donor density, 300 K (Young and Wight [1974]). |
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Electron diffusion length Ln in p-type GaP versus acceptor (Zn) density, 300 K (Young and Wight [1974]). |
| The longest lifetime of holes (undoped GaP) | τp ~ 1·10-6 s |
| Diffusion length Lp = (Dp·τp)1/2 | Lp ~ 20 µm. |
| The longest lifetime of electrons | τn ~ 1·10-7 s |
| Diffusion length Ln = (Dn·τn)1/2 | Ln ~ 7 µm |
| Surface recombination (Gershenzon and Mikulyak [1966]) |
|
20 K |
(0.1 ÷ 3.4)·102 cm/s |
77 K |
(1.1 ÷ 90)·104 cm/s |
300 K |
(0.4 ÷ 2)·106 cm/s |
| Radiative recombination | |
| Band to band radiative recombination coefficient | - 10-13 cm3/s |
| Impurity recombination at 300 K (Yunovich [1972], Bergh and Dean[1976]) |
|
| Zn-O complex (red LED, hν≈1.8 eV, λ≈0.7 µm) | |
Radiative exciton lifetime |
~10-7 s-1 |
Oscillator force for exciton recombination |
0.07 |
Non - radiative exciton lifetime: |
B≈10-10 ÷- 10-11 cm3/s |
Non - radiative single electron lifetime: τcn=1/C·p2 |
C≈10-30 cm6/s |
| N - isoelectron impurity (green LED, hν~2.22 eV, λ~0.56 µm) | |
Radiative exciton lifetime |
- 3·10-8 s |
Oscillator force for exciton recombination |
0.09 |
Bond energy of exciton in GaP doped with N: |
|
|
0.021 eV |
|
0.143 eV |
| Auger recombination coefficient | - 10-30 cm6/s |