Periodic Reporting for period 1 - MP3 (Multi-Potent Polymer Precursor approach for novel conjugated polymers)
Reporting period: 2021-02-01 to 2023-01-31
The MP3 project introduces a new approach for the synthesis of organic semiconductors which allow the preparation of materials characterized by well-defined and complementary electronic properties, which would be otherwise inaccessible. This is made possible by employing a novel class of precursors that are designed to have superior solubility and stability, thus allowing simpler and milder fabrication procedures, and from which one can obtain the target materials during a final, high-yielding, and simple reaction. This approach is often found in the preparation of organic (semi)conductors when the low solubility is an issue.
Unlike other type of precursors, which are designed to yield only one material, the approach developed with MP3 allows the preparation of different materials depending on the final treatment they undergo. In this sense, these latter can display different chemical and electronic properties, while still originating from an identical parent molecule – from this peculiarity originates the name of the project Multi-Potent Polymer Precursors, MP3. Remarkably, one can even obtain semiconducting polymers characterized by complementary electronic properties, i.e. able to transport either holes (p-type transport) or electrons (n-type transport), even from the same precursor layer.
This research can have important implications in diverse and interdisciplinary fields such as organic electronics, conformable devices, and the energy sector. To start, the possibility of achieving complementary transport properties (and p-n junctions) on a single layer is an important step forward toward the fabrication of devices comprising all-organic complex logic gates which require the presence of p and n type regions simultaneously. This is, for example, the case of the ubiquitous silicon-based CMOS technology, however, its analogue in organic electronics is still lacking or requires complex multi-level designs which limits their scope.
The low-bandgap polymers prepared through the MP3 approach also offer interesting redox proprieties which can be useful in the fabrication of thin, low-voltage displays that can find application in conformable devices and e-skin applications to display information in real-time and low energy consumption.
In addition, possible application to the energy sector are particularly appealing, for example as active materials in organic photovoltaics or as electrode material in lithium-batteries or battery technologies based on different, more abundant and environmentally friendly, metal ions. Concerning this latter point, the intrinsic light-weight of these materials and their reliable redox chemistry can result in high capacitance and fast kinetics, two ideal features for the development of the future of batteries.
In particular, the main objective of the MP3 project was to develop an innovative precursor approach which would allow the synthesis and characterization of high-molecular weight, fully-conjugated, organic semiconducting materials with complementary electronic properties, and their implementation in actual devices to harness their properties.
Unlike other type of precursors, which are designed to yield only one material, the approach developed with MP3 allows the preparation of different materials depending on the final treatment they undergo. In this sense, these latter can display different chemical and electronic properties, while still originating from an identical parent molecule – from this peculiarity originates the name of the project Multi-Potent Polymer Precursors, MP3. Remarkably, one can even obtain semiconducting polymers characterized by complementary electronic properties, i.e. able to transport either holes (p-type transport) or electrons (n-type transport), even from the same precursor layer.
This research can have important implications in diverse and interdisciplinary fields such as organic electronics, conformable devices, and the energy sector. To start, the possibility of achieving complementary transport properties (and p-n junctions) on a single layer is an important step forward toward the fabrication of devices comprising all-organic complex logic gates which require the presence of p and n type regions simultaneously. This is, for example, the case of the ubiquitous silicon-based CMOS technology, however, its analogue in organic electronics is still lacking or requires complex multi-level designs which limits their scope.
The low-bandgap polymers prepared through the MP3 approach also offer interesting redox proprieties which can be useful in the fabrication of thin, low-voltage displays that can find application in conformable devices and e-skin applications to display information in real-time and low energy consumption.
In addition, possible application to the energy sector are particularly appealing, for example as active materials in organic photovoltaics or as electrode material in lithium-batteries or battery technologies based on different, more abundant and environmentally friendly, metal ions. Concerning this latter point, the intrinsic light-weight of these materials and their reliable redox chemistry can result in high capacitance and fast kinetics, two ideal features for the development of the future of batteries.
In particular, the main objective of the MP3 project was to develop an innovative precursor approach which would allow the synthesis and characterization of high-molecular weight, fully-conjugated, organic semiconducting materials with complementary electronic properties, and their implementation in actual devices to harness their properties.
In the first part of this project, we have developed a novel class of polymerizable monomers, comprising a 9,10-dihydro-anthracene core functionalized with a propargyl alcohol group, which can be obtained from ready available quinone compounds through a simple and straightforward reaction with an alkylide. Compared to the parent quinones, these monomers display a higher core flexibility and can be further functionalized on the propargyl alcohol group to achieve high solubility, low tendency to form aggregates, and specific chemical responses. Interestingly, these untis can undergo a retro-Favorskii reaction, to revert back to their electron-poor quinoid form, or a reduction-rearomatization, to generate electron-rich ethynyl-substituted acenes. These transformations are particularly appealing as these two forms are characterized by opposite electronic properties.
By polymerizing these monomers, it is therefore possible to transfer these perks – high-solubility, decreased aggregation, possibility of forming quinoid and acene compounds on-demand – to polymers with a high-molecular weight which would not otherwise be accessible. During the middle part of the project, we investigated these possibilities by synthesizing polymers comprising different monomers and several linkers designed to improve further the performances of the materials. We also investigated the possibility of obtaining final target materials characterized by complementary electronic properties from an identical precursor.
Finally, thanks to the information and experience we gather during the project, we developed accessible fabrication procedures to test the performances of the target polymers in actual devices. In particular, we prepared organic field effect transistors (OFETs) and unique multi-colored electrochromic displays comprising a single 20 nm-thick active layer. We chose these two devices to really highlight the different electronic properties of the designed target materials. The possibility of observing the expected behaviors together with the simple procedures developed, indicates that the multipotent precursor approach can offer interesting opportunities to design novel fabrication methodologies and employ materials that would otherwise not be accessible.
The innovative concepts and approaches developed in the MP3 project were collected in a patent and presented at international conferences.
By polymerizing these monomers, it is therefore possible to transfer these perks – high-solubility, decreased aggregation, possibility of forming quinoid and acene compounds on-demand – to polymers with a high-molecular weight which would not otherwise be accessible. During the middle part of the project, we investigated these possibilities by synthesizing polymers comprising different monomers and several linkers designed to improve further the performances of the materials. We also investigated the possibility of obtaining final target materials characterized by complementary electronic properties from an identical precursor.
Finally, thanks to the information and experience we gather during the project, we developed accessible fabrication procedures to test the performances of the target polymers in actual devices. In particular, we prepared organic field effect transistors (OFETs) and unique multi-colored electrochromic displays comprising a single 20 nm-thick active layer. We chose these two devices to really highlight the different electronic properties of the designed target materials. The possibility of observing the expected behaviors together with the simple procedures developed, indicates that the multipotent precursor approach can offer interesting opportunities to design novel fabrication methodologies and employ materials that would otherwise not be accessible.
The innovative concepts and approaches developed in the MP3 project were collected in a patent and presented at international conferences.
During the MP3 project, we developed an innovative precursor route for the fabrication of high-molecular weight, fully-conjugated, semiconducting polymers with different (and complementary) electronic properties from an identical precursor. To the best of our knowledge, this is the first time a multipotent precursor approach is proposed for the synthesis of organic semiconductors. One can design the different precursors to show specific properties and functionalities, thus facilitating the fabrication procedures or the allow the synthesis of otherwise inaccessible materials. This leaves many open questions for the scientific community and provides a novel tool in the hands of material scientists.
At the moment, we are investigating the opportunity to employ the approach defined by MP3 for the preparation of high-specific capacity electrode material for metal-organic batteries and as convenient platform for the preparation of ultra-conformable displays for e-skin applications.
At the moment, we are investigating the opportunity to employ the approach defined by MP3 for the preparation of high-specific capacity electrode material for metal-organic batteries and as convenient platform for the preparation of ultra-conformable displays for e-skin applications.