Unveiling the origin of n-type doping of natural MoS2: carbon

Autor: Youngsin Park, Nannan Li, Daesung Jung, Laishram Tomba Singh, Jaeyoon Baik, Eunsook Lee, Dongseok Oh, Young Dok Kim, Jin Yong Lee, Jeongseok Woo, Seungmin Park, Hanchul Kim, Geunseop Lee, Geunsik Lee, Chan-Cuk Hwang
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: npj 2D Materials and Applications, Vol 7, Iss 1, Pp 1-7 (2023)
Druh dokumentu: article
ISSN: 2397-7132
DOI: 10.1038/s41699-023-00424-x
Popis: Abstract MoS2 has attracted intense interest in many applications. Natural MoS2 and field-effect transistors made of it generally exhibit n-type characteristics, but its origin is unknown. Herein, we show that C is the origin of the universal n-type doping of natural MoS2. Photoemission spectroscopies reveal that while many MoS2 samples with C detected are n-type, some without C exhibit p-type characteristics. The C-free, p-type MoS2 changes to n-type over time with the concurrent appearance of C that is out-diffused from bulk, indicating that C induces the n-type doping. The C-origin is verified by C-deposition and supported by theoretical calculations. This carbon appears as nanometer-scale defects frequently observed in scanning tunneling microscopy. In addition, we propose, based on the calculations, that S vacancies are responsible for the p-type characteristics, which contrasts with the widespread belief. This work provides new perspectives on MoS2 doping and presents a new direction for fabricating reliable MoS2 devices.
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