The competition between quality and productivity has been a major issue for large-scale applications of two-dimensional materials (2DMs). Until now, the top-down mechanical cleavage method has guaranteed pure perfect 2DMs, but it has been considered a poor option in terms of manufacturing. Here, we present a layer-engineered exfoliation technique for graphene that not only allows us to obtain large-size graphene, up to a millimeter size, but also allows selective thickness control. A thin metal film evaporated on graphite induces tensile stress such that spalling occurs, resulting in exfoliation of graphene, where the number of exfoliated layers is adjusted by using different metal films. Detailed spectroscopy and electron transport measurement analysis greatly support our proposed spalling mechanism and fine quality of exfoliated graphene. Our layer-engineered exfoliation technique can pave the way for the development of a manufacturing-scale process for graphene and other 2DMs in electronics and optoelectronics.

The octahedral structure of 2D molybdenum disulfide (1T‐MoS2) has attracted attention as a high‐efficiency and low‐cost electrocatalyst for hydrogen production. However, the large‐scale synthesis of 1T‐MoS2 films has not been realized because of higher formation energy compared to that of the trigonal prismatic phase (2H)‐MoS2. In this study, a uniform wafer‐scale synthesis of the metastable 1T‐MoS2 film is performed by sulfidation of the Mo metal layer using a plasma‐enhanced chemical vapor deposition (PE‐CVD) system. Thus, plasma‐containing highly reactive ions and radicals of the sulfurization precursor enable the synthesis of 1T‐MoS2 at 150 °C. Electrochemical analysis of 1T‐MoS2 shows enhanced catalytic activity for the hydrogen evolution reaction (HER) compared to that of previously reported MoS2 electrocatalysts 1T‐MoS2 does not transform into stable 2H‐MoS2 even after 1000 cycles of HER. The proposed low‐temperature synthesis approach may offer a promising solution for the facile production of various metastable‐phase 2D materials.

The deformation microstructure and creep mechanisms of Zircaloy-4 have been investigated. Four Zircaloy-4 specimens were tested at different temperatures and stress levels and the deformation microstructures of these specimens were analyzed using transmission electron microscopy. On the basis of microstructural observation of a-type screw dislocations in prismatic slip systems, the modified jogged-screw model has been applied as a rate controlling mechanism for creep of Zircaloy-4. In addition, the stress dependency of dislocation density, jog spacing, and jog height has been evaluated via modeling and experimental observations. The purpose of this study is to provide a detailed understanding of the creep deformation of Zircaloy-4 and prediction of creep rates in this alloy based on the microstructural information obtained from TEM analysis.

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Since the first realization of graphene synthesis through the chemical vapor deposition (CVD) method in 2009, CVD‐graphene is regarded as a key material in the future electronics industry, and one that requires high standard characteristics. However, because graphene itself is not a semiconductor, therefore it does not have a bandgap, a promising application is considered to integrate its use with semiconductors, rather than completely replace Si or Ge. Although numerous methods for a clean and uniform graphene transfer process are developed, graphene growth and transfer methods that are applicable to current mainstream Si‐based complementary metal‐oxide‐semiconductor (CMOS) manufacturing processes are not yet introduced. This study implements an eco‐friendly and CMOS‐compatible graphene transfer process through water‐soluble inorganic MoO3 film as a supporting layer. Since the monolayer graphene is grown on hydrogen‐terminated semiconductor Ge surface, the MoO3 thin film coated graphene is easily delaminated from the Ge substrate. The separated graphene could be transferred to arbitrary substrate without a chemical wet etching process, and the remaining Ge substrate could be employed for about 50 times multiple reuse for the growth of graphene, without degradation of the crystallinity of the graphene.