Subnanometer-wide indium selenide nanoribbons

Journal article

Indium selenides (In_xSe_y) have been shown to retain several desirable properties, such as ferroelectricity, tunable photoluminescence through temperature-controlled phase changes, and high electron mobility when confined to two dimensions (2D). In this work we synthesize single-layer, ultrathin, subnanometer-wide In_xSe_y by templated growth inside single-walled carbon nanotubes (SWCNTs). Despite the complex polymorphism of In_xSe_y we show that the phase of the encapsulated material can be identified through comparison of experimental aberration-corrected transmission electron microscopy (AC-TEM) images and AC-TEM simulations of known structures of In_xSe_y. We show that, by altering synthesis conditions, one of two different stoichiometries of sub-nm In_xSe_y, namely InSe or β-In₂Se₃, can be prepared. Additionally, in situ AC-TEM heating experiments reveal that encapsulated β-In₂Se₃ undergoes a phase change to γ-In₂Se₃ above 400 °C. Further analysis of the encapsulated species is performed using X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), energy dispersive X-ray analysis (EDX), and Raman spectroscopy, corroborating the identities of the encapsulated species. These materials could provide a platform for ultrathin, subnanometer-wide phase-change nanoribbons with applications as nanoelectronic components.

Authors: Cull, WJ; Skowron, ST; Hayter, R; Stoppiello, CT; Rance, GA

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: ACS Nano
• Volume: 17
• Issue: 6
• Pages: 6062-6072
• Place of publication: United States
• Publication date: 2023-03-14
• Acceptance date: 2023-03-09
• DOI: 10.1021/acsnano.3c00670
• EISSN: 1936-086X
• ISSN: 1936-0851
• Pmid: 36916820
• Language: English
• Keywords: nanoribbons; carbon nanotubes; indium selenide; III−VI semiconductor; phase change material; nanowires; FFR
• Subjects: Carbon nanotubes; Two dimensional materials; Phase transitions; Encapsulation; Transmission electron microscopy