The current induced by a monochromatic light source in a Schottky barrier or p-n junction perpendicular to the sample surface is analyzed. Expressions for the induced current are derived for a scanning light spot and for uniform illumination with part of the sample shadowed. A uniform illumination induces a current that is more nearly an exponential function of the distance between the junction and the illuminated area than a moving spot. When the effect of surface recombination is strong, an alternative method of deducing the diffusion length from the measured current is suggested. The surface recombination velocity may be determined from the dependence of the collected current on the optical penetration depth in a simple manner.
|Number of pages||4|
|Journal||Solid State Electronics|
|State||Published - 1 Jan 1978|