1. Unveiling the origin of n-type doping of natural MoS2: carbon.
- Author
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Park, Youngsin, Li, Nannan, Jung, Daesung, Singh, Laishram Tomba, Baik, Jaeyoon, Lee, Eunsook, Oh, Dongseok, Kim, Young Dok, Lee, Jin Yong, Woo, Jeongseok, Park, Seungmin, Kim, Hanchul, Lee, Geunseop, Lee, Geunsik, and Hwang, Chan-Cuk
- Subjects
SCANNING tunneling microscopy ,PHOTOELECTRON spectroscopy ,FIELD-effect transistors ,CARBON - Abstract
MoS
2 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. [ABSTRACT FROM AUTHOR]- Published
- 2023
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