Heterogeneous Integration of InGaN Micro-LEDs with a:Si TFT Arrays on Flexible Substrates

In this research, the integration of the GaN micro-LEDs with a-Si:H TFTs on plastics substrate is demonstrated. Considering the thermal limit of the plastic materials, a low-temperature process was developed to fabricate an array of a-Si:H TFTs on a flexible substrate. A wafer bonding and laser-liftoff procedure was used to integrate the LEDs onto the array. The electrical and optical characteristics of the micro-LEDs on flex showed no degradation before and after the transfer process. The electroluminesce of the diodes, within a two-TFT pixel circuit, showed no measurable change in both flat and bent conditions. The proposed methodology may enable the integration of largescale flexible TFT driving circuit with micro-LEDs for deformable display applications.