@misc{EfremenkoLaroussiSengueletal., author = {Efremenko, Yulia and Laroussi, Arwa and Seng{\"u}l, Akant and Corley-Wiciak, Agnieszka Anna and Fischer, Inga Anita and Mirsky, Vladimir M.}, title = {Deposition of Polymers on Titanium Nitride Electrodes}, series = {Coatings}, volume = {14}, journal = {Coatings}, number = {2}, issn = {2079-6412}, doi = {10.3390/coatings14020215}, abstract = {The application of titanium nitride (TiN) as an electrode for electrochemical deposition or characterization requires the removal of an insulating layer from its surface. This process was studied and optimized, and the conditions for the complete removal of this layer through treatment with oxalic acid were formulated. The obtained TiN surfaces were used for the deposition of various conducting and non-conducting polymers. Two different approaches were applied: (i) in situ electrochemical synthesis of the main classes of conducting polymers, including polyaniline, polypyrrole, polythiophene, and selected derivatives thereof, and (ii) electrostatically driven layer-by-layer (LbL) deposition of multilayers of oppositely charged polyelectrolytes. The deposited polymers were characterized by electrochemical methods. The electrochemical properties of the deposited conducting polymers and their deposition on the TiN surface were comparable to those of the metallic electrodes. The films produced via LbL deposition exhibited a pronounced influence of the charge of the last deposited polymer on the redox reaction of ferri/ferrocyanide, validating the charge alteration with each successive polymer layer deposition. The studied deposition technologies can be used for the modification of TiN surfaces required in applications of this material in chemical sensors and other devices.}, language = {en} } @misc{HayatRatzkeAlvaradoChavarinetal., author = {Hayat, Ahsan and Ratzke, Markus and Alvarado Chavarin, Carlos and Z{\"o}llner, Marvin Hartwig and Corley-Wiciak, Agnieszka Anna and Schubert, Markus Andreas and Wenger, Christian and Fischer, Inga Anita}, title = {Structural and morphological properties of CeO2 films deposited by radio frequency magnetron sputtering for back-end-of-line integration}, series = {Thin Solid Films}, volume = {807}, journal = {Thin Solid Films}, issn = {0040-6090}, doi = {10.1016/j.tsf.2024.140547}, pages = {3}, language = {en} } @misc{HayatSpiritoCorleyWiciaketal., author = {Hayat, Ahsan and Spirito, Davide and Corley-Wiciak, Agnieszka Anna and Schubert, Markus Andreas and Masood, Maria and Reichmann, Felix and Ratzke, Markus and Capellini, Giovanni and Fischer, Inga Anita}, title = {MBE-based growth of Sn-rich quantum wells and dots at low Sn deposition rates}, series = {Materials Science in Semiconductor Processing}, volume = {165}, journal = {Materials Science in Semiconductor Processing}, issn = {1873-4081}, doi = {10.1016/j.mssp.2023.107693}, language = {en} } @misc{ReiterRatzkeNitschetal., author = {Reiter, Sebastian and Ratzke, Markus and Nitsch, Paul-Gregor and Mai, Christian and Spirito, Davide and Corley-Wiciak, Agnieszka Anna and Wenger, Christian and Fischer, Inga A.}, title = {Optical response of titanium nitride plasmonic nanohole arrays : impact of square and hexagonal array geometry, pitch, and nanohole diameter}, series = {Plasmonics}, volume = {20}, journal = {Plasmonics}, publisher = {Springer}, address = {New York, NY}, doi = {10.1007/s11468-025-02934-4}, pages = {8825 -- 8834}, abstract = {Plasmonic nanohole arrays (NHAs) exhibit extraordinary optical transmission (EOT) evoked by resonant excitation of surface plasmons at an excitation wavelength, which is highly sensitive to changes in refractive index in the surrounding dielectric. This can enable the use of plasmonic NHAs in on-chip refractive index sensors. Such sensors can be realized on the cost-effective silicon platform by the integration of a plasmonic NHA and a Ge photodetector, provided that complementary metal-oxide-semiconductor (CMOS)-compatible materials are used for their fabrication. Titanium nitride (TiN) as a biocompatible and CMOS-compatible plasmonic transition metal nitride is well-suited for integration on the silicon platform; however, the comparatively large losses within the material require geometry optimization strategies in order to improve the optical properties of TiN NHAs for sensing. In this work, we investigated different TiN NHA geometries both in experiment and simulation. We extensively characterized square and hexagonal arrays with varying pitches and nanohole diameters and provide a detailed comparison of their optical properties. We also discuss characterization results for surface refractive index changes imposed by depositing a thin Al2O3 layer on top of the NHAs. While we do not observe a clear advantage of hexagonal arrays compared to square arrays for sensing, our results highlight the importance of geometry optimization for TiN NHAs integrated with devices.}, language = {en} } @misc{SenguelReiterLotfietal., author = {Seng{\"u}l, Akant and Reiter, Sebastian and Lotfi, Zahra and Efremenko, Julia and Laroussi, Arwa and Corley-Wiciak, Agnieszka Anna and Ratzke, Markus and Mirsky, Vladimir M. and Wenger, Christian and Fischer, Inga Anita}, title = {Titanium nitride plasmonic nanohole arrays with polymer coating : optical properties and their humidity-induced modifications}, series = {Optical materials express}, volume = {16}, journal = {Optical materials express}, number = {2}, publisher = {Optica Publishing Group}, address = {Washington, DC}, issn = {2159-3930}, doi = {10.1364/ome.578871}, pages = {184 -- 196}, abstract = {The use of titanium nitride (TiN) for the fabrication of plasmonic structures such as nanohole arrays (NHAs) can enable their integration into optoelectronic devices on the silicon (Si) platform, for example, for the realization of on-chip chemical sensors and biosensors based on refractometric transduction. With a corresponding functionalization of the TiN nanohole arrays, these ultra-compact devices can be utilized in the development of various affinity sensors and sensor systems, such as cost-effective electronic noses for the early detection of gases in the food industry or agriculture. In this work, we focus on two types of coating for functionalization of TiN nanohole arrays: electrochemically synthesized poly-N-methylaniline and layer-by-layer deposited polyacrylic-acid/poly-allylamine (PAA/PAH). Our investigation comprises the experimental characterization of the optical properties of TiN nanhole arrays coated with polymer layers of different thicknesses as well as a comparison with simulation results. We demonstrate the potential of our setup sensing applications by measuring changes in optical properties of TiN nanohole arrays coated with PAA/PAH upon exposure to air of different humidity.}, language = {en} }