Light Sensing Enhancement and Energy Saving Improvement in Concentric Double-MIS(p) Tunnel Diode Structure With Inner Gate Outer Sensor Operation

Double-metal-insulator-semiconductor tunnel diodes with concentric structure are able to exhibit transistor and light sensor behavior. Generally, the outer ring is used to serve as a control gate and supply additional charges to the inner sensor through coupling. However, there is not yet any discussion about the contrary situation in exchanging the conventional role of the inner device and the outer ring. In this paper, we compare two operating situations with no other variants involved. Comparing the results of them, we find that when the inner device plays as a control gate and the outer ring being a sensor (i.e., inner gate outer sensor), the asymmetric coupling effect can make the outer sensor achieve much higher light-to-dark current ratio, however, only need nearly half of the sensor bias under the same control gate bias. In addition, further calculation of total power consumption shows that there is no larger power needed behind this more sensitive performance compared with the conventional operation.