2D Materials-Assisted Epitaxy and Assembly of Compound Semiconductors for Micro-LED Technology

Heterogeneous integration of functional materials offers exciting new opportunities for advanced device platforms and functional systems. In this talk, I will introduce the integration of III-V and III-N compound semiconductors with 2D materials as a pathway for novel micro-LED platforms.<br/>I will first introduce three epitaxy techniques for synthesizing thin films on 2D materials; remote epitaxy, quasi-van der Waals epitaxy, and selective-area epitaxy [1,2]. I will discuss the challenges and prospects of each approach, in terms of the availability of materials, the quality of as-grown thin films, and the compatibility with various transfer and integration processes.<br/>Second, the application of such techniques for heterogeneous integration will be discussed, with a focus on micro-LED technology. By transferring III-V and III-N LED layers from their host substrates, a vertically stacked RGB structure becomes feasible. The stacked structure can be applied for two distinct applications; small-sized displays with extremely high pixel densities for AR/VR [3], and large-sized micro-LED displays with high efficiency for consumer electronics. Scalable and reliable assembly of pixels is the key for commercialization, and I will discuss approaches for the integration and assembly.<br/><br/><br/>[1] Hyunseok Kim, Yunpeng Liu, Kuangye Lu, Celesta S. Chang, et al., and Jeehwan Kim, “High-throughput manufacturing of epitaxial membranes from a single wafer by 2D materials-based layer transfer process”, Nature Nanotechnology, 18(5), 464-470 (2023).<br/>[2] Hyunseok Kim, Sangho Lee, Jiho Shin, et al., and Jeehwan Kim, “Graphene nanopattern as a universal epitaxy platform for single-crystal membrane production and defect reduction”, Nature Nanotechnology, 17(10), 1054-1059 (2022).<br/>[3] Jiho Shin, Hyunseok Kim, Suresh Sundaram, Junseok Jeong, et al., and Jeehwan Kim, “Vertical full-colour micro-LEDs via 2D materials-based layer transfer”, Nature, 614(7946), 81-87 (2023).