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International audience; Hybrid van der Waals heterostructures made of 2D materials and organic molecules exploit the high sensitivity of 2D materials to all interfacial modifications and the inherent versatility of the organic compounds [1-2]. In this study, we are interested in the quinoïdal zwitterion/MoS2 hybrid system in which organic crystals are grown by epitaxy on the MoS2 surface and can reorganize in other forms after thermal annealing [3]. By means of field effect transistor measurements and atomic force microscopy, we demonstrate that the charge transfer between organic molecules and 2D materials strongly depends on the conformation of the molecular film. This work shows the great sensibility of MoS2 transistors for sensing molecular events occurring at the nanoscale providing a new experimental tool in addition to the usual microscopies and spectroscopies techniques.References :[1] Late, D. J.; Huang, Y.-K.; Liu, B.; Acharya, J.; Shirodkar, S. N.; Luo, J.; Yan, A.; Charles, D.; Waghmare, U. V.; Dravid, V. P.; Rao, C. N. R. Sensing Behavior of Atomically Thin-Layered MoS 2 Transistors. ACS Nano 2013, 7 (6), 4879–4891. [2] Li, N.; Wang, Q.; Shen, C.; Wei, Z.; Yu, H.; Zhao, J.; Lu, X.; Wang, G.; He, C.; Xie, L.; Zhu, J.; Du, L.; Yang, R.; Shi, D.; Zhang, G. Large-Scale Flexible and Transparent Electronics Based on Monolayer Molybdenum Disulfide Field-Effect Transistors. Nat. Electron. 2020, 3 (11), 711–717.[3] Lockhart de la Rosa, C. J.; Phillipson, R.; Teyssandier, J.; Adisoejoso, J.; Balaji, Y.; Huyghebaert, C.; Radu, I.; Heyns, M.; De Feyter, S.; De Gendt, S. Molecular Doping of MoS 2 Transistors by Self-Assembled Oleylamine Networks. Appl. Phys. Lett. 2016, 109 (25), 253112.

International audience; Today, most of electronic devices are based on heterostructures made by molecular beam epitaxy. The impact of van der Waals heterostructures made of 2D materials, already significant at the academic level [1], could generate a technological breakthrough in this field of electronics. Indeed, due to the weak van der Waals interlayer interactions, several materials can be assembled with a precise control of their thicknesses or their twist angles and with high quality interfaces.Recently, hybrid van der waals heterostructures, obtained by combining 2D materials and self-organized organic layers has been developed [2]. Such approach is promising to push further the versatility in terms of materials and thus a wide range of properties are expected.In this poster, we present recent results obtained on field effect transistor based on an hybrid van der Waals heterostructure made of molybdenum disulfide (MoS2) for the inorganic part and quinoidal zwitterions (QZ) for the organic part. The organic layer deposition is achieved under high vacuum, on top of the MoS2 channel of the transistor and the evolution of the transfer characteristic of the transistor is measured in situ.We observed a n-type doping and an increase of the charge carrier density of two orders of magnitudes which is comparable to the doping obtained with optimized charge transfer molecules [3][4]. These results which demonstrate the high compatibility of the QZ with MoS2 open the way for future investigations on functionalized hybrid QZ-2D materials heterostructures[1] A. K. Geim & I. V. Grigorieva Nature 499, 419–425 (2013)[2] Gobbi, M., Orgiu, E., Samorì, P., Adv. Mater. 2018, 30, 1706103.[3] Kiriya, D., Tosun, M., Zhao, P., Kang, J. S., & Javey, A. (2014). Air-Stable Surface Charge TransferDoping of MoS2 by Benzyl Viologen. Journal of the American Chemical Society, 136(22)[4] Dey, S., Matte, H. S. S. R., Shirodkar, S. N., Waghmare, U. V., & Rao, C. N. R. (2013). Charge-Transfer Interaction between Few-Layer MoS2and Tetrathiafulvalene. Chemistry - An Asian Journal,8(8)