Wafer-scale single-crystal two-dimensional materials for integrated optoelectronics

Since the pioneering research on graphene, two-dimensional (2D) materials have been considered as the most promising candidates to continue advancing Moore's Law, and an emerging material family, which has bred a lot of novel functional applications beyond the Si-based integrated circuit. Unfortunately, abundant challenges in the synthesis of wafer-scale single-crystal (WSSC) 2D materials and their on-chip integration technology severely hinder their commercialization road. Over the past few years, significant technique breakthroughs of WSSC 2D materials have been increasingly achieved, accordingly a comprehensive review and critical evaluation of these new advances are pressingly required. In this review article, the outstanding research progress on the synthesis of WSSC 2D materials and 2D material-based on-chip integration technology, including 2D materials integration, nanopatterning, electrode integration, and dielectric integration, are summarized in detail. Then, the major application prospect of different types of WSSC 2D materials in optoelectronics is discussed. Finally, a critical assessment of these advancements is given, as well as the potential challenges and opportunities in the foreseeable future.