Lee Sangho, Zhang Xinyuan, Abdollahi Pooya, Barone Matthew R, Dong Chengye, Yoo Young Jin, Song Min-Kyu, Lee Doyoon, Ryu Jung-El, Choi Jun-Hui, Lee Jae-Hyun, Robinson Joshua A, Schlom Darrell G, Kum Hyun S, Chang Celesta S, Seo Ambrose, Kim Jeehwan
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
ACS Nano. 2024 Nov 12;18(45):31225-31233. doi: 10.1021/acsnano.4c09445. Epub 2024 Oct 29.
Remote epitaxy is taking center stage in creating freestanding complex oxide thin films with high crystallinity that could serve as an ideal building block for stacking artificial heterostructures with distinctive functionalities. However, there exist technical challenges, particularly in the remote epitaxy of perovskite oxides associated with their harsh growth environments, making the graphene interlayer difficult to survive. Transferred graphene, typically used for creating a remote epitaxy template, poses limitations in ensuring the yield of perovskite films, especially when pulsed laser deposition (PLD) growth is carried out, since graphene degradation can be easily observed. Here, we employ spectroscopic ellipsometry to determine the critical factors that damage the integrity of graphene during PLD by tracking the change in optical properties of graphene . To mitigate the issues observed in the PLD process, we propose an alternative growth strategy based on molecular beam epitaxy to produce single-crystalline perovskite membranes.
远程外延在制备具有高结晶度的独立复杂氧化物薄膜方面正占据核心地位，这些薄膜可作为堆叠具有独特功能的人工异质结构的理想构建单元。然而，存在一些技术挑战，特别是在钙钛矿氧化物的远程外延中，由于其苛刻的生长环境，使得石墨烯中间层难以存续。通常用于创建远程外延模板的转移石墨烯，在确保钙钛矿薄膜产量方面存在局限性，尤其是在进行脉冲激光沉积（PLD）生长时，因为很容易观察到石墨烯的降解。在这里，我们采用光谱椭偏仪，通过跟踪石墨烯光学性质的变化来确定在PLD过程中损害石墨烯完整性的关键因素。为了缓解在PLD过程中观察到的问题，我们提出了一种基于分子束外延的替代生长策略，以生产单晶钙钛矿膜。
