Photo-effects in junction field effect transistors

Abstract The current-voltage characteristics of an illuminated junction FET are analyzed for (i) a homogeneous illumination generating electron hole pairs along the entire length of the gate junction and (ii) illumination of a narrow strip extending across the channel. With increasing illumination intensity, a cut-off phenomenon of source or drain photocurrents vs. light intensity occurs, due to the back flow of photocurrents across a forward biased section of the gate junction.