JBD officially released AR glasses with LED micro-display FOV optical waveguide solution

Recently, microled microdisplay manufacturer Shanghai Xianyao Display Technology Jade Bird Display (hereinafter referred to as JBD) officially released the prototype of the Phoenix series of single-chip full-color vertically stacked Micro LED microdisplay screens. The Hummingbird series previously released and in mass production is mainly aimed at AR glasses with optical waveguide solutions at 30 FOV, while the Phoenix series is designed for AR glasses with optical waveguide solutions at more than 50 FOV.

The Phoenix series prototype currently uses a 0.22-inch panel with a resolution of 2K and a sub-pixel equivalent size of 2.5um. Specifically, 22 subpixels are combined into a white pixel with a period of 5um, and the subpixels are driven by 4 independent current channels. Three of the channels are connected to AlInGaN blue, AlInGaN green and AlInGaP red emitters respectively. Most importantly, these semiconductor emitters are stacked vertically and coaxially arranged, as shown in the cross-sectional SEM image in Figure 1. This unique emitter arrangement achieves high WPE and high concentration in the vertical direction. In the future production stage, JBD plans to use the 0.3-inch panel as a standard product, with sub-pixels with 4K resolution and 2um pixel spacing, which is equivalent to white pixels with 2K resolution and 4um pixel spacing.

Monolithic full-color MicroLEDs are the direction that the industry has long pursued for research and development. For example, some start-ups use quantum dots (QD) for color conversion to achieve colored MicroLEDs. However, the maximum brightness and device life of this color conversion method are both There is a great limitation, because the lifetime of quantum dots will decrease significantly as the excitation flux density and the MicroLED junction temperature increase. Other epitaxial-based three-color integration technologies, such as polychromatic epitaxial layers, selective regional epitaxy, regrowth, nanostructures and 3D structures, have not yet been demonstrated with a pixel pitch of less than 10um.

The existing mass-produced full-color MicroLED light engines are made by combining three independent red, green and blue monochromatic panels with X-cube prisms. In contrast, the single-chip RGB full-color MicroLED microdisplay will have wider application value in the future because it can achieve a larger field of view and a smaller light engine shape. In addition, since the system-level integration of AR glasses is simplified and optical losses are reduced, higher waveguide collimation efficiency can be achieved. JBD's Phoenix prototype demonstrates the feasibility of using native semiconductors to achieve a single RGB MicroLED screen with a pitch of less than 5um. Compared with existing single-sided Micro-OLED screens, the brightness is increased by more than 2 orders of magnitude.

Relying on its expertise in wafer-level bonding and thin epitaxy technology, JBD has successfully developed full-color displays using its proprietary multi-layer interconnection technology. Native nitride and phosphide epitaxy and chip processes, such as Mesa etching, passivation and microlens, are based on JBD's award-winning SID 2023 Display of the Year's monochrome panels (currently in mass production), ensuring their manufacturability, efficiency, reliability and collimation are maintained. A main feature of this technology is that the total stack thickness is less than 5um, making it the thinnest stack it has produced to date, minimizing absorption losses within the cavity. Coupled with the ability of native epitaxial materials to emit high flux density light, white balance brightness of up to 1 million nits can be achieved using this platform. Another distinctive feature of full-native color solutions is their ability to achieve narrow Full Width Half Maximum (FWHM) spectra, resulting in images with high color quality and color purity. Figure 2 shows that the full-width maximum FWHM values for red, green and blue pixels are 15nm, 30nm and 18nm, respectively.

Figure 1:(a) a single full-color wafer;(b) a 5um color pixel pitch array;(c) a cross-section image showing vertical stacking and multi-level interconnection technology.

Figure 2. JBD's native color RGB screens have a typical emission spectrum with narrow FWHM.

Li Qiming, founder and CEO of JBD, said: Thanks to the hard work of JBD scientists and engineers, we were able to achieve this engineering feat. The newly released Phoenix series of single-chip full-color platforms provide revolutionary and innovative solutions that open the door to immersive AR glasses. The prospects of AR glasses becoming the next computing platform have become brighter, and we are very excited to embark on this journey with our customers. quot;

Figure 3(a)-(d). Multiple color luminescent images (white, red, green and blue) at the same pixel position, and (e) and (f) are combined to form a full-color picture.

JBD will release a prototype of a monolithic full-color vertically stacked optical engine in the first half of 2024 and plans to put it into mass production in 2025.