Monolithic InGaN multi‐color light‐emitting devices

Given the recent surge of interest in full-color microLED display technologies, researchers in academia and industry have been looking for feasible and cost-effective solutions to realize multicolor emission from a single wafer to overcome the shortcomings of existing “mass transfer” approaches that involve the assembly of huge numbers of chips from multiple wafers. In contrast to such heterogeneous integration approaches, monolithic integration solutions that combine different color emitters onto a single chip or wafer offer potentially higher yield, scalability, robustness, efficiency, and manufacturability. In this review, an overview of the main monolithic integration approaches for the assembly of polychromatic emitters on a chip or wafer, including top-down fabrication and bottom-up growth approaches is given. The successful realization of monolithic polychromatic emission would greatly speed up the development of phosphor-free white light sources, chip-scale color microLED displays, and other GaN-based optoelectronic systems and platforms.