Scholarlink

<p>Surface-enhanced Raman spectroscopy (SERS) by 2D semiconductors relies on chemical (CM) enhancement driven by charge-transfer (CT) processes in bandgap alignment between molecules and substrates. Unfortunately, the low light absorption and weak conferment in the atomic-layer material limit the enhancement factor of Raman intensity (<i>EFRI</i>). Improving the utilization efficiency of excitation light is therefore essential for promoting SERS performance of 2D semiconductors. Here we develop a heterojunction SERS substrate, composed of few-layer MoS<sub>2</sub> (FL-MoS<sub>2</sub>) flakes capping onto the acceptor-rich <i>β</i>-Ga<sub>2</sub>O<sub>3</sub> microstrips grown by optical vapor supersaturated precipitation (OVSP). The acceptor-rich <i>β</i>-Ga<sub>2</sub>O<sub>3</sub> microstrips excited by ultraviolet (UV) irradiation boost the CT processes between FL-MoS<sub>2</sub> and analyte molecules, by which the <i>EFRI</i> was increased by two orders of magnitude up to 9.33 × 10⁴ with the limit of detection (<i>LoD</i>) down to 10<sup>⁻9</sup> M for methylene blue (MB). The in-situ experiment unveils that the SERS improvement is originated from the photoinduced carries trapped by the deep acceptor of Ga<sup>2−</sup> vacancies (<InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11671_2025_4339_Article_IEq1.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">\(\:{V}_{Ga}^{2-}\)</EquationSource> </InlineEquation>) at 2.53&#xa0;eV below conduction band minimum to facilitate the CT resonance. The present work provides new insights into the role of defect states in the chemical SERS mechanism, demonstrating the improvement of 2D-material substrate performance for ultrasensitive Raman detection.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

UV-promoted surface-enhanced Raman spectroscopy via heterojunction of few-layer MoS2 flakes on acceptor-rich β-Ga2O3 microstrips

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年9月5日

查看全文
  • Wenjing Jia,
  • Yinzhou Yan,
  • Yao Yao,
  • Yijian Jiang

摘要

Surface-enhanced Raman spectroscopy (SERS) by 2D semiconductors relies on chemical (CM) enhancement driven by charge-transfer (CT) processes in bandgap alignment between molecules and substrates. Unfortunately, the low light absorption and weak conferment in the atomic-layer material limit the enhancement factor of Raman intensity (EFRI). Improving the utilization efficiency of excitation light is therefore essential for promoting SERS performance of 2D semiconductors. Here we develop a heterojunction SERS substrate, composed of few-layer MoS2 (FL-MoS2) flakes capping onto the acceptor-rich β-Ga2O3 microstrips grown by optical vapor supersaturated precipitation (OVSP). The acceptor-rich β-Ga2O3 microstrips excited by ultraviolet (UV) irradiation boost the CT processes between FL-MoS2 and analyte molecules, by which the EFRI was increased by two orders of magnitude up to 9.33 × 10⁴ with the limit of detection (LoD) down to 10⁻9 M for methylene blue (MB). The in-situ experiment unveils that the SERS improvement is originated from the photoinduced carries trapped by the deep acceptor of Ga2− vacancies ( \(\:{V}_{Ga}^{2-}\) ) at 2.53 eV below conduction band minimum to facilitate the CT resonance. The present work provides new insights into the role of defect states in the chemical SERS mechanism, demonstrating the improvement of 2D-material substrate performance for ultrasensitive Raman detection.