Functional polymers for electronic-structure modulation of MoS$_{2}$

Two-dimensional semiconductors based on the Mo and W family of transition metal dichalcogenides (TMDCs) are emerging as an important class of materials with unique optoelectronic properties. However, there remain challenges associated with precise control over carrier doping and work functions that need to be overcome for device applications. We report the synthesis of new tetrathiafulvalene (TTF)-based polymers that provide enhanced solution stabilization of MoS$_{2}$ nanosheets while simultaneously modulating their electronic structure through robust, non-covalent interactions. Kelvin probe force microscopy (KPFM) imaging of TTF-polymer functionalized 2H MoS$_{2}$ nanosheets confirms n-doping of the MoS$_{2}$ with an accompanying reduction in the work function. Density functional theory calculations provide insight into the TTF-MoS$_{2}$ interfacial interactions and provide a theoretical basis for modulation of electronic properties of MoS$_{2}$ via charge-transfer interactions. These combined results illustrate the potential for polymer doping of TMDCs as a viable and scalable approach for synthesis of new hybrid materials for optoelectronics.