A Novel Architecture for Photovoltaic Devices: Field-effect Solar Cells Using Screening-engineered Nanoelectrodes for Silicon and Earth Abundant Cuprous Oxide

Oscar Vazquez1,2, William Regan1,2, Onur Ergen1,2, Will Gannett1,2, Steven Byrnes1,2, Feng Wang1,2, Alex Zettl1,2 1Department of Physcis, University of California, Berkeley, Berkeley, CA, United States /2Materials Science Division, Lawrence Berkeley National Laboratory, CA, United States

We present a novel photovoltaic cell architecture based on the field effect that controls carrier concentration in semiconductors using screening-engineered nanostructured electrodes. The device operates in inversion mode with a top gate that forms a p-n junction and with nanostructured electrodes that collect the photocurrent across the junction. This architecture does not require any doping process or a heterojunction, opening an alternative path to fabricate cells on hard-to-dope materials such as oxides or phosphides. As a proof of concept, we present a field effect solar cell made of Si. To demonstrate the potential of this configuration for alternative materials, we also present a field-effect solar cell made of cuprous oxide, which has a favorable band gap but that is difficult to dope. We show that the behavior of the devices is controlled by the gate voltage that forms an inversion layer and hence a rectifying p-n junction.