Evolution of the Electronic Gap of Directly Synthesized Versus Mechanically Transferred WS2 Monolayer to Multilayer Films

• DOI: 10.1002/admi.202401008
• Publication Date: 2025-03-11T16:03:02Z
• Authors: Xu He; Jinpeng Tian; Wenjing Wu; Satya Butler; Shengxi Huang; Saien Xie; Antoine Kahn

Abstract The electronic properties of 2D materials play a critical role in determining their potential for device applications. Despite rapid developments semiconductors, studies fundamental parameters, including the gap and ionization energy, are limited, with significant discrepancies reported values. study focuses on tungsten disulfide (WS₂) investigates structure films comprising an increasing number layers deposited two different methods: direct synthesis via metal–organic chemical vapor deposition (MOCVD) additive mechanical transfer exfoliated single layers. characterized Raman, UV–vis, photoluminescence spectroscopies, as well ultraviolet photoelectron inverse photoemission spectroscopies (UPS/IPES). WS₂ is found to decrease from 2.43 eV monolayer 1.97 trilayer, indicating bulk transition at trilayer thickness. This reduction primarily due downward shift conduction band minimum relative valence maximum. A comparative analysis MOCVD‐grown reveals slightly larger samples, attributed differences defect densities. levels evaluated through UPS/IPES highlight influence preparation methods WS₂.