Internal talk - MoS2 Inks for Opto-Electronic flexible devices

Thu., March 9, 2023, 1 p.m.
This seminar is held online.
Online: https://tinyurl.com/nanoSeminar-GA

Google Scholar


Solution-processed semiconducting transition metal dichalcogenides (TMDs) are a hot-topic research trend in printed (opto)-electronics.
Indeed, liquid phase exfoliation is an efficient strategy to convert bulk layered materials into thin nanosheets dispersed in a suitable solvent1. The obtained inks can be printed into thin films using several approaches, including ink-jet printing, screen printing, and spray coating2, thereby promoting the advances of printed electronics where low-cost and large-area fabrication is as relevant as device performance. However, the device performance is limited by structural defects resulting from the exfoliation process and poor inter-flake electronic connectivity within the films. The formation of covalent interconnected networks of TMDs potentially represent an efficient strategy to simultaneously heal sulfur vacancies and bridge adjacent flakes, thereby generating percolation pathways for the charge transport, ultimately boosting the electrical performance3.
Here, we unveil the charge transport mechanisms of printed devices based on covalent MoS2 networks via multiscale analysis, by comparing the effects of aromatic vs. aliphatic dithiolated linkers. Temperature-dependent electrical measurements reveal hopping as the dominant transport mechanism and a novel analysis based on percolation theory attributes the superior performance of devices functionalized with π-conjugated molecules to the improved inter-flake electronic connectivity and formation of additional percolation paths. Our findings provide valuable guidelines for improving the charge transport properties in MoS2 devices based on covalent networks.
References
1. Hernandez, Y. et al. High-yield production of graphene by liquid-phase exfoliation of graphite. Nat. Nanotechnol. 3, 563–568 (2008).
2. Pinilla, S., Coelho, J., Li, K., Liu, J. & Nicolosi, V. Two-dimensional material inks. Nat. Rev. Mater. 7, 717–735 (2022).
3. Ippolito, S. et al. Covalently interconnected transition metal dichalcogenide networks via defect engineering for high-performance electronic devices. Nat. Nanotechnol. 16, 592–598 (2021).


Brief CV

Francesca Urban received her Ph.D. at University of Salerno in 2021. Starting from October 2020, she has been working as Maire Curie Fellow in Nanochemistry group of Prof. Paolo Samorì at Institut de Science et d’Ingénierie Supramoléculaires.
Her research activity is mainly focused on the fabrication, characterization, and functionalization of 2D material-based devices taking advantage of molecular chemistry approaches for (opto)electronic and sensing applications.
Francesca is author of more than 40 peer-reviewed papers and guest editor of the Special Issue “Two-Dimensional Materials For (Opto)-Electronic Applications”.
In Feb 2023, she visited the chair of Prof. Gianaurelio Cuniberti to study the use of H2S to heal MoS2 defects and its applications in sensor devices.



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Internal talk - MoS2 Inks for Opto-Electronic flexible devices

Thu., March 9, 2023, 1 p.m.
This seminar is held online.
Online: https://tinyurl.com/nanoSeminar-GA

Google Scholar


Solution-processed semiconducting transition metal dichalcogenides (TMDs) are a hot-topic research trend in printed (opto)-electronics.
Indeed, liquid phase exfoliation is an efficient strategy to convert bulk layered materials into thin nanosheets dispersed in a suitable solvent1. The obtained inks can be printed into thin films using several approaches, including ink-jet printing, screen printing, and spray coating2, thereby promoting the advances of printed electronics where low-cost and large-area fabrication is as relevant as device performance. However, the device performance is limited by structural defects resulting from the exfoliation process and poor inter-flake electronic connectivity within the films. The formation of covalent interconnected networks of TMDs potentially represent an efficient strategy to simultaneously heal sulfur vacancies and bridge adjacent flakes, thereby generating percolation pathways for the charge transport, ultimately boosting the electrical performance3.
Here, we unveil the charge transport mechanisms of printed devices based on covalent MoS2 networks via multiscale analysis, by comparing the effects of aromatic vs. aliphatic dithiolated linkers. Temperature-dependent electrical measurements reveal hopping as the dominant transport mechanism and a novel analysis based on percolation theory attributes the superior performance of devices functionalized with π-conjugated molecules to the improved inter-flake electronic connectivity and formation of additional percolation paths. Our findings provide valuable guidelines for improving the charge transport properties in MoS2 devices based on covalent networks.
References
1. Hernandez, Y. et al. High-yield production of graphene by liquid-phase exfoliation of graphite. Nat. Nanotechnol. 3, 563–568 (2008).
2. Pinilla, S., Coelho, J., Li, K., Liu, J. & Nicolosi, V. Two-dimensional material inks. Nat. Rev. Mater. 7, 717–735 (2022).
3. Ippolito, S. et al. Covalently interconnected transition metal dichalcogenide networks via defect engineering for high-performance electronic devices. Nat. Nanotechnol. 16, 592–598 (2021).


Brief CV

Francesca Urban received her Ph.D. at University of Salerno in 2021. Starting from October 2020, she has been working as Maire Curie Fellow in Nanochemistry group of Prof. Paolo Samorì at Institut de Science et d’Ingénierie Supramoléculaires.
Her research activity is mainly focused on the fabrication, characterization, and functionalization of 2D material-based devices taking advantage of molecular chemistry approaches for (opto)electronic and sensing applications.
Francesca is author of more than 40 peer-reviewed papers and guest editor of the Special Issue “Two-Dimensional Materials For (Opto)-Electronic Applications”.
In Feb 2023, she visited the chair of Prof. Gianaurelio Cuniberti to study the use of H2S to heal MoS2 defects and its applications in sensor devices.



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