Scholarlink

<p>Platinum diselenide (PtSe<sub>2</sub>) exhibits a distinctive thickness-modulated metal-to-semiconductor transition, which makes it suitable for diverse applications in nanoelectronics and optoelectronics. This study systematically investigates the spatiotemporal dynamics of photoexcited carrier relaxation in PtSe<sub>2</sub>. Through temperature-dependent ultrafast spectroscopy, two distinct low-frequency acoustic phonons (AP) were identified in multilayer PtSe<sub>2</sub>. Transient absorption microscopy (TAM) measurements reveal thickness-dependent relaxation dynamics and distinct carrier diffusion behavior in multilayer PtSe<sub>2</sub>. These findings indicate superior carrier transport properties, with a measured mobility of 394.1±38.5 cm<sup>2</sup>·V<sup>−1</sup>·s<sup>−1</sup> for multilayers. Temperature-dependent ultrafast dynamics, acquired using a custom-built cryogenic pump-probe system, reveal two coherent AP modes, <i>ω</i><sub>1</sub> and <i>ω</i><sub>2</sub>, with central frequencies of 1.27 and 0.17 THz, respectively. The higher frequency <i>ω</i><sub>1</sub> mode corresponds to shear mode with a nominal electron-phonon coupling constant <i>λ</i><sub><i>ω</i>1</sub> = 2.22. To our knowledge, this study represents a pioneering investigation that employs low-temperature ultrafast spectroscopy to elucidate the AP mode and strong electron-phonon coupling in semimetallic PtSe<sub>2</sub> systems. These findings offer fundamental insights into the semimetallic nature of PtSe<sub>2</sub> and establish a basis for designing ultrafast photonic devices that harness its distinct optoelectronic response.</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

Probing strong electron-phonon coupling in semimetallic PtSe2 via ultrafast optical spectroscopy

  • 期刊论文

  • 发表日期：

    2026年3月18日

查看全文
  • Shu-yu Liu,
  • Qi-yi Wu,
  • Chen Zhang,
  • Xin Li,
  • Quan Long,
  • Hao-lin Chang,
  • Ying-wei Wang,
  • Jun He,
  • Jian-qiao Meng

摘要

Platinum diselenide (PtSe2) exhibits a distinctive thickness-modulated metal-to-semiconductor transition, which makes it suitable for diverse applications in nanoelectronics and optoelectronics. This study systematically investigates the spatiotemporal dynamics of photoexcited carrier relaxation in PtSe2. Through temperature-dependent ultrafast spectroscopy, two distinct low-frequency acoustic phonons (AP) were identified in multilayer PtSe2. Transient absorption microscopy (TAM) measurements reveal thickness-dependent relaxation dynamics and distinct carrier diffusion behavior in multilayer PtSe2. These findings indicate superior carrier transport properties, with a measured mobility of 394.1±38.5 cm2·V−1·s−1 for multilayers. Temperature-dependent ultrafast dynamics, acquired using a custom-built cryogenic pump-probe system, reveal two coherent AP modes, ω1 and ω2, with central frequencies of 1.27 and 0.17 THz, respectively. The higher frequency ω1 mode corresponds to shear mode with a nominal electron-phonon coupling constant λω1 = 2.22. To our knowledge, this study represents a pioneering investigation that employs low-temperature ultrafast spectroscopy to elucidate the AP mode and strong electron-phonon coupling in semimetallic PtSe2 systems. These findings offer fundamental insights into the semimetallic nature of PtSe2 and establish a basis for designing ultrafast photonic devices that harness its distinct optoelectronic response.