Tunable Current Transport in PdSe2 via Layer-by-Layer Thickness Modulation by Mild Plasma

Tanmoy Das, Dongwook Seo, Jae Eun Seo, Jiwon Chang

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

The thickness-modulated phase transition from semi-metallic (bulk) to semiconductor (a few layers) is the most unique property of pentagonal palladium diselenide (PdSe2). Thus, precise thickness tailoring is essential to fully utilize its unique thickness-dependent property for exotic device applications. Here, tunable current transport in PdSe2 based field-effect transistors (FETs) enabled by layer-by-layer thinning of PdSe2 using mild SF6:N2 plasma is presented. With this top-down plasma-etching method, the PdSe2 layer thickness can be precisely modulated without structural degradation, which paves the way to realize the complete potential of PdSe2-based devices. By modifying the plasma power and exposure time, an atomic layer precision etching rate of 0.4 nm min−1 can be achieved. Atomic-force microscopy, Raman spectroscopy, and secondary ion mass spectrometry confirm the uniform and complete removal of top layers of PdSe2 flake over a large area without affecting remaining bottom layers. Electrical characterization of current transport in plasma-thinned PdSe2 FETs reveals excellent layer-dependent conductivity similar to pristine PdSe2 FETs. This simple but highly scalable and controllable plasma-etching technique provides a promising way to fabricate PdSe2 devices based on lateral heterostructures composed of different thicknesses PdSe2 flakes to exploit strongly thickness-dependent electronic structures.

Original languageEnglish
Article number2000008
JournalAdvanced Electronic Materials
Volume6
Issue number5
DOIs
Publication statusPublished - 2020 May 1

Bibliographical note

Funding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2017R1C1B5015940 and 2018R1D1A1B0741867). The authors would like to acknowledge Dr. Da Luo from IBS Center for Multidimensional Carbon Materials (CMCM), UNIST for Raman characterization support of PdSe2.

Funding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2017R1C1B5015940 and 2018R1D1A1B0741867). The authors would like to acknowledge Dr. Da Luo from IBS Center for Multidimensional Carbon Materials (CMCM), UNIST for Raman characterization support of PdSe. 2

Publisher Copyright:
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials

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