Simultaneous Light Communication and Sensing of a Multi-Quantum Well Diode

When a multi-quantum well (MQW) diode is biased with a forward voltage and illuminated with an external shorter-wavelength light, the device simultaneously emits and senses light, with the injected current and the induced current mixed inside the wells. Here, we have developed a dual-function MQW diode utilizing the standard LED fabrication process flow and have experimentally demonstrated its capability to communicate and sense light simultaneously, eliminating the need for voltage switching between emitting and detecting modes. The results indicate that MQW diodes have the potential to be used as light emitting units in interactive human-computer displays.