Reversal of the Current from a Cuprous Oxide Photo Cell in Red Light

Abstract

WHILE testing the sensitivity of photo cells of the rectifier type for various wave-lengths, we have observed a small reverse current with a cell of the ‘Serpidox’ make exposed to red light. As we have seen no reference to this effect, a few details may be worth noting. The cell is a commercial form of that described by M. Auger, the cuprous oxide film being covered with a thin conducting film, which we believe to be of gold. Contact is made with the latter by a metal ring, the inner edge of which forms the rim of the pupil, 17 mm. in diameter.