Non-linear electrical effect in graded-electron concentration silicon

A gradient of carrier concentration in semiconductors can create a double-frequency internal electric field which is parallel to this gradient and perpendicular to the applied a.c. field. This warm-carrier effect was measured in silicon specimens with a gradient of electron concentration, at 77 and 300 K, under applied fields from 1 to 10 V m^-1 and within the frequency range of 0.3–20 kHz. A comparison between experimental data and a theoretical model is discussed.