Ultraviolet-Visible Dual-Band Mini-Sized Light Emitting and Detecting Diode Toward Optical Communication

Optical wireless communication (OWC) systems play an essential role in constructing next-generation networks for data transmission, acquisition, and processing. However, most OWCs typically work in a single operation band and are deployed with single-wavelength light emitting or detecting devices, limiting their functionality and capacity to meet the increasing demands in versatile and complex scenarios. Herein, we report a deep ultraviolet-visible dual-band mini-sized light emitting and detecting diode with controllable dual-wavelength operation characteristics, enabled by on-chip integration of two diodes sharing a common n-electrode while one diode selectively coated with quantum dots. Remarkably, our devices demonstrate high optical bandwidths of 222 MHz and 96 MHz and data rate of 540 and 340 Mbps using on-off keying (OOK) modulation scheme at the emission of 275 and 470 nm when employed in an OWC, respectively, enabling the capability of real-time encrypted data transmission of ASCII code signals. Additionally, the up-conversion of the deep ultraviolet-to-visible optical signal can also be realized on such monolithically integrated two diodes, while using one diode as a detector and another as an emitter. The proposed device architecture offers a multifunctional optoelectronic device platform for building next-generation high-speed solar-blind and visible OWCs in free-space and underwater communication applications.