MicroLED

Abstract: microLED arrays are a route to providing emissive displays with high brightness and low power consumption performance. In this talk we will discuss results pertaining to sub 10 μm LED pixels, the challenges posed and performance achieved in forming microLED arrays. In particular, pixel pitch, backplane capabilities and colourisation. The applications which can benefit from this approach will also be discussed.

Abstract: The overarching goal of an active contact lens is to integrate sensing or display functionality onto a wearable device, enabling on-lens medical monitoring and heads-up displays. We present progress toward a wirelessly-powered active contact lens comprising a transparent polymer substrate, loop antenna, power harvesting IC, and a custom micro-LED. The fully integrated radio power harvesting and a power management system was fabricated in a 0.13μm CMOS process and utilizes a small on-chip capacitor as an energy storage element to light up a microLED pixel. We have demonstrated wireless power transfer and LED intensity control using the custom IC and on-lens antenna.

Abstract: We report high resolution (873 x 500), active-matrix, GaN-based LED microdisplays with a pixel pitch of 10 μm. They exhibit the highest resolution for the smallest pixel pitch ever reported for GaN microdisplays. High-density GaN μLED arrays were first patterned at 10-μm pitch on sapphire substrates. Arrays were then hybridized on CMOS active-matrix using the microtube technology. Blue and green monochrome prototypes have been realized. Full video, high-resolution images have been obtained. The performance of these GaN-based microdisplays make them suitable for a wide range of applications from augmented reality and head-up displays to pico- and compact projectors.

Abstract: MicroLED arrays with the capability of switching each pixel separately with high frequency can serve as structured micro-illumination light engines for applications in sensing, optogenetics, microscopy and many others. We describe a scalable chip process chain for the fabrication of passive-matrix microLED arrays, which were integrated with PCB-based driving electronics. The arrays were produced by deep-etching of conventional planar LED structures on sapphire, followed by filling and planarization steps. The pixel resolution lies in the range of 254 to 2540 pixels-per-inch (ppi), the arrays consist of 32 x 32 pixels. Optical output powers up to 50 µW per pixel were measured. In comparison to CMOS-based approaches, the presented technology is a simplified strategy to produce microLED arrays with high pixel counts.