Ternary Transition Metal Chalcogenide Nb<sub>2</sub>Pd<sub>3</sub>Se<sub>8</sub>: A New Candidate of 1D Van der Waals Materials for Field‐Effect Transistors
Byung Joo Jeong, Kyung Hwan Choi, Jiho Jeon, Sang Ok Yoon, You Kyoung Chung, Dongchul Sung, Sudong Chae, Bum Jun Kim, Seungbae Oh, Sang Hoon Lee, Chaeheon Woo, Tae Yeong Kim, Jungyoon Ahn, Jae‐Hyun Lee, Joonsuk Huh, Hak Ki Yu, Jae‐Young Choi
Abstract
Abstract In this work, high‐quality 1D van der Waals (vdW) Nb 2 Pd 3 Se 8 is synthesized, showing an excellent scalability from bulk to single‐ribbon due to weakly bonded repeating unit ribbons. The calculation of electronic band structures confirmed that this novel Nb 2 Pd 3 Se 8 is a semiconducting material, displaying indirect‐to‐direct bandgap transition with decreasing the number of unit‐ribbons from bulk to single. Field effect transistors (FETs) fabricated on the mechanically exfoliated Nb 2 Pd 3 Se 8 nanowires exhibit n‐type transport characteristics at room temperature, resulting in the values for the electron mobility and I on / I off ratio of 31 cm 2 V −1 s −1 and ≈ 10 4 , respectively. Through transport measurements at various temperatures from room temperature down to 90 K, it is confirmed that Nb 2 Pd 3 Se 8 FETs can achieve negligible Schottky barrier height (SBH) for the Au contacts at the temperature range, displaying clear ohmic contact characteristics. Furthermore, top‐gated FETs fabricated with the Al 2 O 3 dielectric layer are studied simultaneously with back‐gated FETs.