The research field of graphene has been rapidly expanded ever since its first experimental realization of Dirac fermions in 2005, due to the fundamental importance in physics as a new paradigm for relativistic condensed matter physics as well as a potential building block for next generation device applications. Most of the intriguing physics observed so far in graphene can be traced to its peculiar electron band structure, which is in analogy with relativistic Dirac fermions. This article reviews recent progress in graphene research that has been done using angle-resolved photoemission technique, the most direct probing tool of the electron band structure. In particular, we discuss a few examples of novel properties so far explored ranging from the basic electron band structure to complicated many-body interactions.

Chalcogenide and oxide heterostructures have been studied as a next-generation electronic materials, due to their interesting electronic properties, such as direct bandgap semiconductor, ferroelectricity, ferromagnetism, superconductivity, charge-density waves, and metal-insulator transition, and their modification near heterointerfaces, so called, electronic reconstruction. An angle-resolved photoemission spectroscopy (ARPES) is a powerful technique to unveil such novel electronic phases in detail, especially combined with high quality thin film preparation methods, such as, molecular beam epitaxy and pulsed laser deposition. In this article, the recent ARPES results in chalcogenide and oxide thin films will be introduced.

wo dimensional (2D) van der Waals (vdW) nanosheet semiconductors have recently attracted much attention from researchers because of their potentials as active device materials toward future nano-electronics and -optoelectronics. This review mainly focuses on the features and applications of state-of-the-art vdW 2D material devices which use transition metal dichalcogenides, graphene, hexagonal boron nitride (h-BN), and black phosphorous: field effect transistors (FETs), complementary metal oxide semiconductor (CMOS) inverters, Schottky diode, and PN diode. In a closing remark, important remaining issues of 2D vdW devices are also introduced as requests for future electronics and photonics applications.