Shanghai, China, 28 August, 2023: Jade Bird Display (JBD), a world leader in MicroLED technology has announced prototype shipments of Phoenix series, which is the highly anticipated single panel monolithic RGB MicroLED micro-displays. While the Hummingbird, previously released and currently in volume production, targets 30-degree FOV application, the Phoenix series is designed to be used with 50+ degree FOV waveguides.
The current engineering samples of Phoenix adopts 0.22” panel, with 2K resolution and 2.5um sub pixel pitch. A 2X2 array of sub-pixels are combined in a 5um-pitch white pixel with 4 individual current driving channels. Three of these channels are individually connected with the AlInGaN blue emitter, AlInGaN green emitter, and AlInGaP red emitter. Most importantly, these semiconductor emitters are vertically stacked and coaxially aligned, as shown in the cross-sectional SEM image in Figure 1. This unique emitter arrangement allows high WPE and highly converged light emission in the vertical directions. In the future production stage, JBD projects a 0.3” panel as a standard product, with 4K resolution of 2 um sub pixel pitch, equivalent to a 2K resolution of 4 um white pixel pitch.
To-date, color conversion using quantum-dots (QD) remains the most common method towards realizing a monolithic RGB display. This down-conversion approach is currently limited in terms of the maximum achievable brightness and device lifetime, since QD lifetime degrades significantly with increasing pumping flux density and microLED junction temperatures. Alternative epitaxy-based techniques to integrate three colors such as multi-color epilayers, selective area epitaxy, regrowth, nanostructures and 3D structures have yet to produce convincing prototypes at < 10 um pixel pitch. Existing full color MicroLED displays are achieved by combining three separate monochrome red, green and blue panels with an X-cube prism. A single panel monolithic RGB micro-display is ultimately preferred, as it enables larger field of view and smaller form factor light engines. In addition, higher collimation efficiency into waveguides is achievable due to reduced optical losses from the simplified system level integration onto AR glasses. However, MicroLED-based ultra-fine pitch (< 5 um) full color monolithic panels for AR applications remains elusive due to technical challenges associated with integrating three colors onto a single wafer. JBD’s Phoenix prototype demonstrates the feasibility of sub 5 um pitch monolithic RGB MicroLED micro-displays using native semiconductors, which translates to over 2 orders of magnitude higher brightness compared to incumbent single panel Micro-OLED displays.
Leveraging its expertise in wafer level bonding and thin-epi technology, JBD has successfully developed the polychrome display using its proprietary multi-level interconnect technology. The native nitride and phosphide-epitaxy and chip processes such mesa etch, passivation and microlens are based on JBD’s award winning ‘SID 2023 Display of the Year’ monochrome panels currently in mass production, thus ensuring that its manufacturability, high wall plug efficiencies, proven reliability and narrow beam collimation is maintained. A key feature of the technology is the total stack thickness of less than 5 um, which is the thinnest ever produced and acts to minimize absorption losses within the cavity. Coupled with the ability to operate the native color light sources at high flux density, white-balanced brightness up to 1 million nits can be achieved using this platform. Another striking characteristic of an all-native color solution is the ability to achieve narrow full width at half maximum (FWHM) spectrum, which leads to high color quality and color purity images. Figure 2 illustrates FWHM of 15 nm, 30 nm and 18 nm achieved for the red, green, and blue pixels respectively.
Figs 1. (a) Completed Polychrome wafer, (b) 45-degree tilt SEM image of 5 um color pixel pitch arrays, and (c) focused ion beam cut and cross-sectional SEM image of multi-level interconnect technology, electrical connection schedule is not shown.
Fig. 2. Typical red, green and blue electroluminescence spectra with narrow FWHM from JBD’s native color 5.0 um pitch monolithic RGB microdisplay.
JBD founder and CEO Qiming Li said: “Thanks to the hard work of JBD’s scientists and engineers, an engineering feat has been achieved”. The polychrome platform offers game changing innovative solutions and open the doors for immersive AR glasses. The prospect for AR glasses to be the next computing platform has never been brighter and we are excited to be in this journey together with our customers”.
Figs 3(a)-(d). Optical microscopic images of the various color emission of the same pixel locations, and (e),(f) optical images displayed from 5.0 μm pixel pitch technology.
JBD will showcase prototypes of the native color monolithic polychrome projectors at various industry events in the first half of 2024. Mass production of these panels is scheduled for 2025. The company welcomes potential partners to design-in the monolithic full color projector into their next generation glasses.
About Jade Bird Display:
Founded in 2015, JBD has been focusing on developing the smallest, brightest, and most efficient micro-display panels. With a fab established in Hefei CHINA, JBD is considered as one of the leaders in microLED display technologies with its portfolio of active matrix microLED displays.