Formation of Highly Doped Nanostripes in 2D Transition Metal Dichalcogenides via a Dislocation Climb Mechanism. Issue 12 (19th February 2021)

• Record Type: Journal Article
• Authors: Lin, Yung‐Chang; Karthikeyan, Jeyakumar; Chang, Yao‐Pang; Li, Shisheng; Kretschmer, Silvan; Komsa, Hannu‐Pekka; Chiu, Po‐Wen; Krasheninnikov, Arkady V.; Suenaga, Kazu
• Is Part Of: Advanced materials. Volume 33:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-19
• Subjects: dislocation migration -- doping -- nanostripes -- transition metal dichalcogenides; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202007819
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Doping of materials beyond the dopant solubility limit remains a challenge, especially when spatially nonuniform doping is required. In 2D materials with a high surface‐to‐volume ratio, such as transition metal dichalcogenides, various post‐synthesis approaches to doping have been demonstrated, but full control over spatial distribution of dopants remains a challenge. A post‐growth doping of single layers of WSe2 is performed by adding transition metal (TM) atoms in a two‐step process, which includes annealing followed by deposition of dopants together with Se or S. The Ti, V, Cr, and Fe impurities at W sites are identified by using transmission electron microscopy and electron energy loss spectroscopy. Remarkably, an extremely high density (6.4–15%) of various types of impurity atoms is achieved. The dopants are revealed to be largely confined within nanostripes embedded in the otherwise pristine WSe2 . Density functional theory calculations show that the dislocations assist the incorporation of the dopant during their climb and give rise to stripes of TM dopant atoms. This work demonstrates a possible spatially controllable doping strategy to achieve the desired local electronic, magnetic, and optical properties in 2D materials. Abstract : A new strategy to dope transition metal dichalcogenides (TMDC) is demonstrated in which a high density (6.4–15%) of dopants is confined within 1D nanostripes embedded in the TMDC lattice. The growth of the nanostripe structures originates from the migration of dislocation cores and is also the key to introduce dopants into 2D materials.