Dual-polarity output response-based photoelectric devices

Photoelectric devices converting information carried by light into useful electrical signals are widely studied. To date, many mechanisms are applied to the design of photoelectric devices, such as the photovoltaic (PV) effect, photothermoelectric (PTE) effect, and photoelectrochemical (PEC) effect. When designing photoelectric devices that take advantage of these mechanisms, the polarity of the photocurrent is sensitive not only to light intensity but also to other parameters, including the wavelength of the incident light, pressure, and solutes. Here, development of these devices is summarized with a focus on working mechanisms, strategies to control the polarity of photocurrents, general performance, and potential applications, especially PEC effect-based devices for biosensing and PV effect-based devices for wavelength discrimination. The polarity switching phenomenon endows photoelectric devices with multi-functional characteristics that may offer new solutions to address traditional issues and meet the requirements of future technologies.