Function File: `mu` = **osc_mobility_poolefrenkel** (`u0, de0, Teff, beta, gamma, vmax`)

Poole-Frenkel mobility model:

`mupf`` = `

`u0`` * exp (- (`

`de0``/(K_b *`

`Teff``)) + sqrt(abs(E)) * ((`

`beta``/(Kb `

`T_eff``))- `

`gamma``) `

`mulim`` = `

`vmax``/abs(E) `

`mu`` = 1/((1/`

`mupf``)+(1/`

`mulim``)) `