Enhanced Visible-Light Response of Ultrathin Er-Doped MoS<sub>2</sub> Nanosheets through a Wet-Chemical Method
Lei Wang, Enhai Song, Shuai Zhang, Xiaoshi Hou, Xiaohong Ji, Qinyuan Zhang
Abstract
Doping is one of the important technologies for modifying the properties of two-dimensional (2D) transition metal dichalcogenides (TMDs). Herein, ultrathin Er-doped MoS 2 nanosheets with an enhanced visible-light response have been synthesized by a wet-chemical method. The few-layer characteristic of the MoS 2:Er nanosheets is beneficial from the H 2 S generated during the preparation process. Near-infrared emission at ∼1530 nm from MoS 2:Er nanosheets has been observed under 980 nm laser excitation, which corresponds to the energy transition from 4 I 13/2 to 4 I 15/2 of Er 3+ . Meanwhile, the enhanced visible-light response of MoS 2:Er has been demonstrated by the photocatalytic performance (removing rhodamine B) and photocurrent response compared with undoped MoS 2 . Based on the experiments and density functional theory calculation, the enhanced visible-light response is attributed to the improved separation capability of photogenerated electron–hole pairs of the ultrathin MoS 2:Er nanosheets. Er-doping induces an increase of S vacancies and the energy transfer between Er 3+ ions and the host. The work demonstrates a developed universal and recyclable synthesis strategy for various metal-doped MoS 2 nanosheets and their applications in the fields of photocatalysis and photodetection.