Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warszawa, Poland.
Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 25 rue des Martyrs, 38000 Grenoble, France.
Nanoscale. 2023 Apr 13;15(15):6941-6946. doi: 10.1039/d2nr04844b.
Using four-wave mixing microscopy, we measure the coherent response and ultrafast dynamics of excitons and trions in MoSe monolayers grown by molecular beam epitaxy on thin films of hexagonal boron nitride. We assess inhomogeneous and homogeneous broadenings in the transition spectral lineshape. The impact of phonons on the homogeneous dephasing is inferred the temperature dependence of the dephasing. Four-wave mixing mapping, combined with atomic force microscopy, reveals spatial correlations between exciton oscillator strength, inhomogeneous broadening and the sample morphology. The quality of the coherent optical response of epitaxially grown transition metal dichalcogenides now becomes comparable to the samples produced by mechanical exfoliation, enabling the coherent nonlinear spectroscopy of innovative materials, like magnetic layers or Janus semiconductors.
利用四波混频显微镜，我们测量了在六方氮化硼薄膜上通过分子束外延生长的 MoSe 单层中的激子和三激子的相干响应和超快动力学。我们评估了跃迁谱线形状的非均匀和均匀展宽。通过温度对退相的依赖性推断出了声子对均匀退相的影响。四波混频映射，结合原子力显微镜，揭示了激子振子强度、非均匀展宽和样品形貌之间的空间相关性。现在，外延生长的过渡金属二卤化物的相干光响应质量可以与机械剥落法制备的样品相媲美，从而实现了对创新材料（如磁性层或 Janus 半导体）的相干非线性光谱学研究。
