# Life Time and Diffusion Length in Silicon

| Here are some values in tabulated form taken from data given by Wacker Siltronic.
|  | Note that the conversion between diffusion length L and lifetime t involves the diffusion constant D via L = (D t)1/2 which in turn contains the mobility µ via D = (kT/e) · µ.
|  | The mobility µ, however, is a function of doping type and doping level. It comes as no surprise that the table must distinguish between doping type and level - and the differences can amount to a factor of 3!
Diffusion- length L [µm] | Carrier Lifetime [µs]
n-type | p-type
10 Wcm | 100 Wcm | 10 Wcm | 100 Wcm
--- | --- | --- | ---
100 | 8 | 8 | 3 | 3
200 | 34 | 32 | 13 | 11
300 | 76 | 72 | 30 | 24
400 | 135 | 129 | 54 | 44
500 | 211 | 201 | 84 | 68
700 | 414 | 394 | 165 | 133
1 000 | 845 | 804 | 336 | 2723
5 000 | 21 121 | 20 109 | 8393 | 6 798

With frame

3.1.1 Silicon: General Properties and Technologies

© H. Föll (Semiconductors - Script)