Simulation of Visible Light Induced Effects in a Tunnel Junction Array for Photonic Device Applications

Publisher Website
Google Scholar
Abstract
We have studied visible light or near-infrared irradiation effects in voltage-biased tunnel junction arrays, where each node is connected not only to neighboring nodes but to a conducting substrate through a tunnel barrier. Major assumptions used in the simulation are: (i) that the photoexcitation of electrons occurs only in the substrate and (ii) the tunnel barrier is effectively lowered for the excited electrons, resulting in a reduced tunnel resistance. As a result, it was found that a U-shaped potential profile is formed by local irradiation and the potential of the irradiated area is clamped at the lowest value. Since the currents at both terminals reflect the left and the right potential slopes in the dark areas, respectively, the irradiated position is determined by measuring the currents. These results suggest that tunnel junction arrays can be applied to photonic devices such as position sensing detectors or image processing devices.