Mesoporous GaN Distributed Bragg Reflectors

Distributed Bragg reflectors (DBRs) are essential components for the development of optoelectronic devices. For many device applications, it is highly desirable to achieve not only high reflectivity and low absorption, but also good conductivity to allow effective electrical injection of charges. Here, we demonstrate the wafer-scale fabrication of highly reflective and conductive non-polar gallium nitride (GaN) DBRs, consisting of perfectly lattice-matched non-polar (11–20) GaN and mesoporous GaN layers that are obtained by a facile one-step electrochemical etching method. The GaN/mesoporous GaN DBRs exhibit high peak reflectivities (>96%) across the entire visible spectrum and wide stop-band widths (full-width at half-maximum >80 nm), while preserving the material quality and showing good electrical conductivity. Such mesoporous GaN DBRs thus provide a promising and scalable platform for high performance GaN-based optoelectronic, photonic, and quantum photonic devices.

Figure: Illustration of wafer-scale fabrication of highly reflective GaN/mesoporous GaN distributed Bragg reflectors and the ability to tune the spectral response across the entire visible spectrum.