Step engineering for nucleation and domain orientation control in WSe2 epitaxy on c-plane sapphire

Haoyue Zhu; Nadire Nayir; Tanushree H Choudhury; Anushka Bansal; Benjamin Huet; Kunyan Zhang; Alexander A Puretzky; Saiphaneendra Bachu; Krystal York; Thomas V Mc Knight; Nicholas Trainor; Aaryan Oberoi; Ke Wang; Saptarshi Das; Robert A Makin; Steven M Durbin; Shengxi Huang; Nasim Alem; Vincent H Crespi; Adri C T van Duin; Joan M Redwing

doi:10.1038/s41565-023-01456-6

Step engineering for nucleation and domain orientation control in WSe₂ epitaxy on c-plane sapphire

Nat Nanotechnol. 2023 Nov;18(11):1295-1302. doi: 10.1038/s41565-023-01456-6. Epub 2023 Jul 27.

Authors

Haoyue Zhu^#¹, Nadire Nayir^#^{1

2

3}, Tanushree H Choudhury^#^{1

4}, Anushka Bansal⁵, Benjamin Huet¹, Kunyan Zhang⁶, Alexander A Puretzky⁷, Saiphaneendra Bachu⁵, Krystal York⁸, Thomas V Mc Knight⁵, Nicholas Trainor⁵, Aaryan Oberoi⁹, Ke Wang¹⁰, Saptarshi Das^{1

9}, Robert A Makin⁸, Steven M Durbin⁸, Shengxi Huang^{6

11}, Nasim Alem^{1

5}, Vincent H Crespi^{1

12}, Adri C T van Duin^{1

3}, Joan M Redwing^{13

14}

Affiliations

¹ 2D Crystal Consortium Materials Innovation Platform, Materials Research Institute, The Pennsylvania State University, University Park, PA, USA.
² Department of Physics, Karamanoglu Mehmetbey University, Karaman, Turkey.
³ Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, USA.
⁴ Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, India.
⁵ Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA.
⁶ Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, USA.
⁷ Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
⁸ Department of Electrical Engineering, Western Michigan University, Kalamazoo, MI, USA.
⁹ Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA.
¹⁰ Materials Research Institute, The Pennsylvania State University, University Park, PA, USA.
¹¹ Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA.
¹² Department of Physics, The Pennsylvania State University, University Park, PA, USA.
¹³ 2D Crystal Consortium Materials Innovation Platform, Materials Research Institute, The Pennsylvania State University, University Park, PA, USA. [email protected].
¹⁴ Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA. [email protected].

^# Contributed equally.

PMID: 37500779
DOI: 10.1038/s41565-023-01456-6

Abstract

Epitaxial growth of two-dimensional transition metal dichalcogenides on sapphire has emerged as a promising route to wafer-scale single-crystal films. Steps on the sapphire act as sites for transition metal dichalcogenide nucleation and can impart a preferred domain orientation, resulting in a substantial reduction in mirror twins. Here we demonstrate control of both the nucleation site and unidirectional growth direction of WSe₂ on c-plane sapphire by metal-organic chemical vapour deposition. The unidirectional orientation is found to be intimately tied to growth conditions via changes in the sapphire surface chemistry that control the step edge location of WSe₂ nucleation, imparting either a 0° or 60° orientation relative to the underlying sapphire lattice. The results provide insight into the role of surface chemistry on transition metal dichalcogenide nucleation and domain alignment and demonstrate the ability to engineer domain orientation over wafer-scale substrates.