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 pixelsper-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.

GaN microLED technology has the potential to offer displays with high brightness, bandwidth, and long lifetime with a very low energy consumption. Moreover, GaN‐on‐Si hybrid interconnection technology allows the development of displays with a very high pixel density integration. In this work we present an in‐pixel driving circuit designed in a 0.18µm CMOS technology to be integrated on a 512x512 microLED array by using the KlettWelding hybrid interconnection technique forming a microLED display of 1411 ppi with 10kfps working speed. The pixel driver is able to achieve switching times of 1MHz and can be operated at high bias currents of 120µA. The individual driver consists of 4 SRAMs that apply a weighted current and allows to avoid the current stability problems associated to CMOS backplanes in hybridly interconnected displays.

No abstract

No abstract

No abstract