Dalgleish Simon, Reissig Louisa, Shuku Yoshiaki, Ligorio Giovanni, Awaga Kunio, List-Kratochvil Emil J W
Department of Chemistry and IRCCS, Nagoya University, Furo-cho, Chikusa, 464-8602, Nagoya, Japan.
Institut für Physik, Institut für Chemie & IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 6, 12489, Berlin, Germany.
Sci Rep. 2019 Nov 13;9(1):16682. doi: 10.1038/s41598-019-53186-2.
Near-infrared sensitization of monolayer MoS is here achieved via the covalent attachment of a novel heteroleptic nickel bis-dithiolene complex into sulfur vacancies in the MoS structure. Photocurrent action spectroscopy of the sensitized films reveals a discreet contribution from the sensitizer dye centred around 1300 nm (0.95 eV), well below the bandgap of MoS (2.1 eV), corresponding to the excitation of the monoanionic dithiolene complex. A mechanism of conductivity enhancement is proposed based on a photo-induced flattening of the corrugated energy landscape present at sulfur vacancy defect sites within the MoS due to a dipole change within the dye molecule upon photoexcitation. This method of sensitization might be readily extended to other functional molecules that can impart a change to the dielectric environment at the MoS surface under stimulation, thereby extending the breadth of detector applications for MoS and other transition metal dichalcogenides.
通过将一种新型的异质镍双二硫纶配合物共价连接到MoS结构中的硫空位上，实现了单层MoS的近红外敏化。敏化薄膜的光电流作用光谱显示，敏化剂染料在1300 nm（0.95 eV）附近有一个明显的贡献，远低于MoS的带隙（2.1 eV），这对应于单阴离子二硫纶配合物的激发。基于光激发时染料分子内偶极子变化导致MoS内硫空位缺陷位点处波纹状能量景观的光致变平，提出了一种电导率增强机制。这种敏化方法可能很容易扩展到其他功能分子，这些分子在刺激下可以改变MoS表面的介电环境，从而扩展MoS和其他过渡金属二硫属化物的探测器应用范围。
