Usman Arslan, Adel Aly M, Masenda Hilary, Thompson Joshua J P, Gunasekera Surani M, Mucha-Kruczyński Marcin, Brem Samuel, Malic Ermin, Koch Martin
Department of Physics and Materials Sciences Centre, Philipps-Universität Marburg, Marburg 35032, Germany.
Department of Physics, COMSATS University Islamabad-Lahore-Campus, Pakistan.
Nanoscale. 2022 Aug 4;14(30):10851-10861. doi: 10.1039/d2nr01973f.
Two-dimensional (2D) semiconductors have opened new horizons for future optoelectronic applications through efficient light-matter and many-body interactions at quantum level. Anisotropic 2D materials like rhenium disulphide (ReS) present a new class of materials with polarized excitonic resonances. Here, we demonstrate a WSe/ReS heterostructure which exhibits a significant photoluminescence quenching at room temperature as well as at low temperatures. This indicates an efficient charge transfer due to the electron-hole exchange interaction. The band alignment of two materials suggests that electrons optically injected into WSe are transferred to ReS. Polarization resolved luminescence measurements reveal two additional polarization-sensitive exciton peaks in ReS in addition to the two conventional exciton resonances X and X. Furthermore, for ReS we observe two charged excitons (trions) with binding energies of 18 meV and 15 meV, respectively. The bi-excitons of WSe become polarization sensitive and inherit polarizing properties from the underlying ReS layers, which act as patterned substrates for top layer. Overall, our findings provide a better understanding of optical signatures in 2D anisotropic materials.
二维（2D）半导体通过量子水平上高效的光与物质及多体相互作用，为未来的光电子应用开辟了新视野。像二硫化铼（ReS）这样的各向异性二维材料呈现出一类具有极化激子共振的新型材料。在此，我们展示了一种WSe/ReS异质结构，其在室温以及低温下均表现出显著的光致发光猝灭。这表明由于电子 - 空穴交换相互作用而实现了高效的电荷转移。两种材料的能带排列表明，光注入到WSe中的电子会转移到ReS。偏振分辨发光测量揭示，除了两个传统的激子共振峰X和X之外，ReS中还有另外两个对偏振敏感的激子峰。此外，对于ReS，我们观察到两个带电激子（三重子），其结合能分别为18毫电子伏特和15毫电子伏特。WSe的双激子变得对偏振敏感，并从作为顶层图案化衬底的下层ReS层继承了偏振特性。总体而言，我们的研究结果有助于更好地理解二维各向异性材料中的光学特征。
