Monolithic integration of GaN Micro-LEDs to active matrix driving transistors made on transfer-free graphene

Journal article, 2025

Traditional semiconductor used as channel materials in driving transistors suffer from significant performance degradation as the semiconductor thickness is reduced. The two-dimensional (2D) materials with smooth, dangling-bond-free surfaces, represented by graphene, can be alternatives. Graphene boasts several advantages, including structural stability, ultra-thin thickness, near-total transparency, exceptional flexibility, and high mobility. Therefore, graphene field-effect transistors (GFETs) in the paper are used to drive Micro-light-emitting diodes (Micro-LEDs), key elements in next-generation advanced displays due to their high resolution, high brightness, high contrast, etc. Importantly, this study addresses the two major bottlenecks i.e. Micro-LEDs’ mass transfer and graphene transfer. That is, monolithically integrated devices of Micro-LED and its driver GFET are designed and fabricated, bypassing the issue of traditional Micro-LEDs’ mass transfer. For the first time, transfer-free method by plasma-enhanced chemical vapor deposition (PECVD) is used to grow graphene directly on GaN Micro-LED samples and prepared graphene transistors. This approach avoids doping and damage to the graphene during the transfer process, significantly shortens the growth time, and improves the fabrication efficiency. The devices possess broad applications potential and compatibility with semiconductor planar processes. This study paves the way for the transfer-free growth of graphene and the integration of Micro-LEDs with 2D materials transistors.