| 학회 | 한국재료학회 |
| 학술대회 | 2021년 가을 (11/24 ~ 11/26, 경주 라한호텔) |
| 권호 | 27권 2호 |
| 발표분야 | 특별심포지엄 6. 메타버스 광기능/디스플레이 심포지엄-오거나이저: 심우영(연세대) |
| 제목 | In-Plane Heterostructures of Graphene and Hexagonal Boron Nitride |
| 초록 | Two-dimensional (2D) heterostructures combining several individual 2D materials provide unique platforms to create unprecedented physical properties, thereby exploring new applications. In particular, heterostructures of hexagonal boron nitride (h-BN) and graphene have attracted a great deal of attention for potential applications. Although several methods have been developed to produce in-plane heterostructures of graphene and h-BN through the partial substitution reaction of graphene, the reverse reaction has not been reported. Though the endothermic nature of this reaction might account for the difficulty and previous absence of such a process, we demonstrated a new chemical route in which the Pt substrate plays a catalytic role. We also proposed that this reaction proceeds through h-BN hydrogenation; subsequent graphene growth quickly replaces the initially etched region. Importantly, this conversion reaction enabled the controlled formation of patterned in-plane graphene/h-BN heterostructures, without needing the commonly employed protecting mask, simply by using a patterned Pt substrate [1]. It means that we could fabricate spatially controlled in-plane heterostructures of h-BN and graphene. We expanded the spatially controlled conversion of h-BN to graphene on an array of Pt nanoparticles (NPs) to realize an array of uniform GQDs embedded in an h-BN sheet. A uniform Pt NP array was formed on a SiO2/Si substrate with the aid of self-patterning diblock copolymer micelles, and the h-BN sheet was transferred on the Pt NPs array, followed by the conversion of h-BN on Pt to GQDs. The size of the obtained GQDs corresponded with the sizes of the Pt NPs, because of the selective conversion of h-BN on top of Pt NPs. Uniform and precisely controlled size of the GQDs ranging from 7 to 13 nm was achieved. Finally, we demonstrated electron transport by the size-controlled GQDs isolated by insulating h-BN like a Coulomb blockade, indicating that the splitting energy of the GQD is 70–140 meV, compatible with its dimension [2]. In addition, a new photoluminescence peak in the GQD/h-BN heterostructures was observed at 410 nm. This blue-emitting photoluminescence occurs at 1D heterojunctions of h-BN and graphene, which is originated from the localized energy states at the disordered boundaries of h-BN and graphene [3]. [1] G. Kim, et al., Nano Letters 15, 4769 (2015) [2] G. Kim, et al., Nature Communications 10, 230 (2019) [3] G. Kim, et al., Nature Communications 11, 5359 (2020) |
| 저자 | Hyeon Suk Shin |
| 소속 | Department of Chemistry and Low-Dimensional Carbon Materials Center |
| 키워드 | |
