Question

onvold 3.16P) The figure shows electric field versus drift velocity and current density (solid lines) for a semiconductor. a) Determine what parameter you can found by calculating the tangent of solid lines (dashed lines). b) Explain why the current density saturates. Explain why the current density higher for electrons or lower for holes. (Explain using formulation and with one or two sentences) hoes

Answer 1

1) from the graph between current density and electric field slope of curve gives conductivity of electrons and holes as,

$\sigma= \frac{dJ}{dE}$

And the graph between drift velocity and electric field slope curve gives mobility of electrons and holes as,

$\mu= \frac{dv_d}{dE}$

2) after applying sufficient electric field we overce the potential barrier of semiconductor due to which current through semiconductor saturates after threshold electric field .

Due to higher mobility of electrons than hole current density of electrons is greater than hole.