Monomolecular Membrane-Assisted Growth of Antimony Halide Perovskite/MoS<sub>2</sub> Van der Waals Epitaxial Heterojunctions with Long-Lived Interlayer Exciton
Zhicheng Zhou, Juntong Zhu, Lutao Li, Wang Chen, Changwen Zhang, Xinyu Du, Xiangyi Wang, Guoxiang Zhao, Ruonan Wang, Jiating Li, Zheng Lu, Yi Zong, Yinghui Sun, Mark H. Rümmeli, Guifu Zou
Abstract
Epitaxial growth stands as a key method for integrating semiconductors into heterostructures, offering a potent avenue to explore the electronic and optoelectronic characteristics of cutting-edge materials, such as transition metal dichalcogenide (TMD) and perovskites. Nevertheless, the layer-by-layer growth atop TMD materials confronts a substantial energy barrier, impeding the adsorption and nucleation of perovskite atoms on the 2D surface. Here, we epitaxially grown an inorganic lead-free perovskite on TMD and formed van der Waals (vdW) heterojunctions. Our work employs a monomolecular membrane-assisted growth strategy that reduces the contact angle and simultaneously diminishing the energy barrier for Cs 3 Sb 2 Br 9 surface nucleation. By controlling the nucleation temperature, we achieved a reduction in the thickness of the Cs 3 Sb 2 Br 9 epitaxial layer from 30 to approximately 4 nm. In the realm of inorganic lead-free perovskite and TMD heterojunctions, we observed long-lived interlayer exciton of 9.9 ns, approximately 36 times longer than the intralayer exciton lifetime, which benefited from the excellent interlayer coupling brought by direct epitaxial growth. Our research introduces a monomolecular membrane-assisted growth strategy that expands the diversity of materials attainable through vdW epitaxial growth, potentially contributing to future applications in optoelectronics involving heterojunctions.