Monolithic integration of III-nitride voltage-controlled light emitters with dual-wavelength photodiodes by selective-area epitaxy.

We report for the first time on-chip integration of III-nitride voltage-controlled light emitters with visible and ultraviolet (UV) photodiodes (PDs). InGaN/GaN and AlGaN/GaN heterostructures were grown in specific regions by selective-area epitaxy, allowing monolithic integration of versatile devices including visible light emitting diodes (LEDs), visible-light PDs, AlGaN/GaN high electron mobility transistors (HEMTs), and UV-light Schottky barrier (SB) PDs. A serial connection between the LED and HEMT through the epitaxial layers enables a three-terminal voltage-controlled light emitter (HEMT-LED), efficiently converting voltage-controlled signals into visible-light signals that can be coupled into an adjacent visible-light PD generating electrical signals. While the integrated blue HEMT-LED and PD transmits signals carried by visible light, the visible-blind SB-PD on a chip receives external UV light control signals with negligible interference from the on-chip visible-light source. This integration scheme can be extended to open an avenue for developing a variety of applications, such as smart lighting, on-chip optical interconnect, optical wireless communication, and opto-isolators.