Diffusion length

Diffusion length

The diffusion length is the average distance that the excess carriers can cover before they recombine. Diffusion length depends on the lifetime and mobility of the carriers.

Note: Diffusion factor (D) is not a constant, but depents on the carrier mobility.

For the resolution of every electrical measurement the diffusion length is the limitation. For a measurement of high quality silicon samples a maximal resolution of about 1 mm can be achieved.