Superlinearity in a Bi-implanted CdS thin film

Bi ion implantation with post annealing of CdS thin films results in good photo-conductor. Superlinearity of photocurrent with light intensity is observed in ion implanted CdS thin films at high light intensity. A numerical two-state model that predicts the superlinearity of the photoconductor is discussed. This model confirms the existence of the insensitive, superlinear and saturated regions of the photocurrent-light intensity curve. Experimental results verify the computer-generated theoretical curve.