IRTG 2022 "ATUMS" - Project 2.

Project 2. Semiconductor@polymer and Semiconductor@TiO2 hybrids


TUM: Nilges, Müller-Buschbaum, Becherer
UofA: Mar, Hegmann, Shankar
Students: Annabelle Degg, Kathrin Vosseler, Philipp Deng


Abstract:

During the first ATUMS phase we exploited the recently discovered semiconducting material SnIP and acquired decent knowledge on its utilization in functional hybrid materials. We showed that SnIP can successfully be incorporated in different standard polymers like polyethylene oxide (PEO), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), or polyvinylidenfluorid (PVP) as well as in TiO2 nanotube membranes. Due to the beneficial flexibility of SnIP, which is caused by the double helical crystal structure, such hybrids are potential candidates for flexible electronic devices (the polymer hybrids) or water splitting catalysts, solar cell components or sensors.

We expect to additionally influence the band structure of the hybrid materials by the elemental composition in SnIP-related inorganic semiconductors of the general formula MXPn where M = Sn, Pb, X = Cl, Br, I, and Pn = P, As. This will allow beneficial band alignment in MXPn species for the specifically aimed application. Assessment of the properties and fabrication of the prototype devices will be performed within the project collaboration network.

 

According to the results within this ATUMS project, SnIP forms core-shell structures with 2D materials as for example graphitic carbon nitride. Another promising class of semiconducting 2D material for the hybridization with SnIP are MXenes, which are synthesized out of the parent layered ternary transition metal carbide, nitride or carbonitride (MAX phase) as for example Ti3AlC2 by HF etching. Due to their broad variety in transition metals, MXenes show potential for applications such as water splitting or sensors.

Ongoing globalization, digitalization and demands for higher standards of living in our society result in a constantly increasing need for energy. Thermoelectric materials, which enable the direct conversion of heat into electricity, can make a significant emission-free contribution to solving our energy problem. Although many compounds with thermoelectric properties are known, the materials are mostly unsuitable for commercial usage due to low efficiency. Representatives from the class of coinage metal chalcogenide halides such as Ag10Te4Br3 and Ag18Cu3Te11Cl3, however, exhibit high Seebeck values as well as a huge drop of thermopower during phase transition resulting in a pnp-switch and thus allow for additional functionality. In comparison to traditional inorganic counterparts, conductive polymers possess advantages such as lower density and thermal conductivity as well as better flexibility and portability. The hybridization with pnp-switchable semiconductors can lead to synergistic effects, making use of the benefits of both materials.