Thickness-Dependence Electrical Characterization of the One-Dimensional van der Waals TaSe₃ Crystal

• Main Authors: Bum Jun Kim, Byung Joo Jeong, Seungbae Oh, Sudong Chae, Kyung Hwan Choi, Tuqeer Nasir, Sang Hoon Lee, Hyung Kyu Lim, Ik Jun Choi, Min-Ki Hong, Hak Ki Yu, Jae-Hyun Lee, Jae-Young Choi
• Format: Article
• Language: English
• Published: MDPI AG 2019-08-01
• Series: Materials
• Subjects: TaSe₃; mechanical exfoliation; work function; van der Waals crystal; scanning Kelvin probing microscopy
• Online Access: https://www.mdpi.com/1996-1944/12/15/2462

Needle-like single crystalline wires of TaSe₃ were massively synthesized using the chemical vapor transport method. Since the wedged-shaped single TaSe₃ molecular chains were stacked along the b-axis by weak van der Waals interactions, a few layers of TaSe₃ flakes could be easily isolated using a typical mechanical exfoliation method. The exfoliated TaSe₃ flakes had an anisotropic planar structure, and the number of layers could be controlled by a repeated peeling process until a monolayer of TaSe₃ nanoribbon was obtained. Through atomic force and scanning Kelvin probe microscope analyses, it was found that the variation in the work function with the thickness of the TaSe₃ flakes was due to the interlayer screening effect. We believe that our results will not only help to add a novel quasi-1D block for nanoelectronics devices based on 2D van der Waals heterostructures, but also provide crucial information for designing proper contacts in device architecture.