본 연구는 화학기상증착(Chemical Vapor Deposition, CVD)로 성장한 이황화몰리브덴(Molybdenum Disulfide, MoS2)

박막을 아르곤(Argon, Ar) 플라즈마를 이용해 표면 황 공극(Sulfur vacancy, S-vacancy)을 선택적으로 도입할 수 있는

공정을 연구하였다. 플라즈마 노출 시간을 2–16 s로 조절하며 라만 분광법(Raman spectroscopy), 원자힘현미경(Atomic

Force Microscopy, AFM), X선 광전자 분광법(X-ray Photoelectron Spectroscopy, XPS), 오제 전자 분광법(Auger Electron

Spectroscopy, AES)을 적용한 결과, 2–8 s 구간에서 구조 손상 없이 S 원자가 우선적으로 제거되는 결함-우선 영역

(defect-first window)이 도출되었다. Raman 및 AFM 분석을 통해 MoS2의 결함을 확인하였다. XPS에서 S/Mo 원자비

감소를 통하여 선택적 S 제거가 정량적으로 입증되었으며, AES 분석을 통해 경향성을 확립하였다. 이러한 공정 조건은

문헌에서 보고된 S-vacancy 기반 전기화학 활성도 향상, 전하 전달 저항 감소(charge transfer resistance reduction),

이중층 정전용량 증가(double-layer capacitance, Cdl), 전기화학적 유효 표면적 증가(electrochemically active surface

area, ECSA)와 부합하며, MoS2 표면 기능화 및 촉매 반응성 향상을 위한 효과적인 전처리 전략으로 활용 가능함을

제시한다.

This study investigates a plasma-based process for the selective introduction of surface sulfur vacancies (Svacancies)

in molybdenum disulfide (MoS2) thin films grown by chemical vapor deposition (CVD) using argon (Ar)

plasma. By varying the plasma exposure time from 2 to 16 s and employing Raman spectroscopy, atomic force microscopy

(AFM), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES), a defect-first window was

identified in the 2–8 s range, where sulfur atoms are preferentially removed without structural damage. Raman and AFM

analyses confirmed defect formation, while XPS revealed a decrease in the S/Mo atomic ratio, quantitatively verifying

selective sulfur removal. AES further confirmed the same trend with enhanced surface sensitivity. These conditions are

consistent with literature reports on S-vacancy-induced improvements in electrochemical activity, including reduced

charge transfer resistance, increased double-layer capacitance (C_dl), and enlarged electrochemically active surface area

(ECSA). This approach provides an effective low-damage pretreatment strategy for MoS₂ surface functionalization and

enhanced catalytic reactivity.

MoS2, Sulfur vacancy, Ar plasma

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