Anomalous layer-dependent photoluminescence spectra of supertwisted spiral WS 2

作者：Minru Qi, Tong Tong, Xiaopeng Fan, Xiangdong Li, Shen Wang, Guofeng Zhang, Ruiyun Chen, Jianyong Hu, Zhichun Yang, Ganying Zeng, Chengbing Qin, Liantuan Xiao, Suotang Jia · 发表于：Optics Express · 年份：2024 · DOI：10.1364/oe.516177 · 被引用次数：8 · 研究领域：2D Materials and Applications、MXene and MAX Phase Materials、Advanced biosensing and bioanalysis techniques

Twisted stacking of two-dimensional materials with broken inversion symmetry, such as spiral MoTe 2 nanopyramids and supertwisted spiral WS 2 , emerge extremely strong second- and third-harmonic generation. Unlike well-studied nonlinear optical effects in these newly synthesized layered materials, photoluminescence (PL) spectra and exciton information involving their optoelectronic applications remain unknown. Here, we report layer- and power-dependent PL spectra of the supertwisted spiral WS 2 . The anomalous layer-dependent PL evolutions that PL intensity almost linearly increases with the rise of layer thickness have been determined. Furthermore, from the power-dependent spectra, we find the power exponents of the supertwisted spiral WS 2 are smaller than 1, while those of the conventional multilayer WS 2 are bigger than 1. These two abnormal phenomena indicate the enlarged interlayer spacing and the decoupling interlayer interaction in the supertwisted spiral WS 2 . These observations provide insight into PL features in the supertwisted spiral materials and may pave the way for further optoelectronic devices based on the twisted stacking materials.