Exploiting Luminescence Emissions of Solar Cells for Optical Frequency Identification (OFID)

This paper presents a new solution for Internet-of-Things (IoT) applications in which GaAs solar cells are employed to transmit information. Transmission of information with a solar cell is possible by modulating the photo-luminescence and the electro-luminescence emissions of the solar cell. Photo-luminescence is modulated with switch to short circuit the solar cell terminals. Electro-luminescence modulation is achieved by applying a time-varying voltage to the cell. The solar cell can also be used to receive information encoded as light intensity variations. Moreover, the solar cell can also be used for its intended function of harvesting ambient radiant energy. Hence, a device equipped with a GaAs solar cell can reuse its on-board solar cell for multiple purposes resulting in devices with lower cost, size and complexity. The proposed devices, which are called Optical Frequency Identification (OFID) devices, are suitable for IoT applications in which wireless communications and energy harvesting are required features. A number of experiments are presented to demonstrate the validity of the proposed solution.