Over the past two decades, organic semiconductors played a growing part as active layers in several electronic systems such as sensors, field‑effect transistors or light emitting diodes to cite a few. In fact, organic materials offer a high versatility and flexibility. However, pure organic systems often lack stability and robustness, which can be overcome by combining them with inorganic scaffolds. In this work, a conducting polymer, polypyrrole (PPy) is employed to create new sensor elements based on the combination of both inorganic and organic layers. Electrical measurements, infrared spectroscopy and current sensing atomic force microscopy provides a better understanding of the polymer behavior upon immersion in aqueous solutions. The observed discharge in water leads to a straightforward application of the device as an in‑flow sensor for several acids like HCl, H2SO4 and H3PO4. The wide range of sensing concentrations as well as the low detection limit place the present detector among the best reported so far in the literature. In a further step to turn towards lab‑in‑a‑tube devices, tubular‑shaped‑integrated microelectrodes are developed by using the rolled‑up technology. As a proof of concept, the successful integration of PPy as an active layer and its use as a gas sensor for volatile organic compounds (VOCs) is demonstrated. Finally, by adapting the rolled‑up top electrodes, as developed by Bof Bufon et al. for self‑assembled monolayers (SAMs), thin PPy films (<50 nm) are vertically contacted and their electrical characteristics measured as a function of temperature and electric field. From the transport investigations, it is observed that an insulating‑to‑metallic transition occurs in the polymeric film by increasing the bias voltage. Other molecular layers like CuPc can be incorporated in these platforms, opening the way towards emerging organic devices.

The combination of modern self-assembly techniques with well-established top-down processing methods pioneered in the electronics industry is paving the way for increasingly sophisticated devices in the future[1]. Nanomembranes, made from a variety of materials, can provide the necessary framework for a diverse range of device structures incorporating wrinkling, buckling, folding, and rolling of thin films[2, 3]. Over the past decade, an elegant symbiosis of bottom-up and top-down methods has been developed, allowing the fabrica- tion of hybrid layer systems via the controlled release and rearrangement of inherently strained layers [4]. Self-assembled rolled-up structures[4, 5] have become increasingly at- tractive in a number of fields including micro/nano uidics[6], optics[7](including metama- terial optical fibers[8]), Lab on a Chip applications[9], and micro- and nanoelectronics[10]. The use of such structures for microelectronic applications has been driven by the versatility in contacting geometries and the abundance of material combinations that these devices offer. By allowing devices to expand in the third dimension, certain obstacles that inhibit 2D structuring can be overcome in elegant ways. Similarly, recent progress in nanostructured superconducting electronic structures has been receiving increased attention[11]. The advancement of such devices has been mo- tivated by their use in quantum computation[12], high sensitivity radiation sensors[13], precision voltage standards[14] and superconducting spintronics[15] to name a few. Combining semiconductor with superconductor materials to create new hybrid geometries is advantageous because it adds the functionalities of the semiconductor, including high charge carrier mobilities, gating possibilities, and refined processing technologies. The main focus of the work presented in this thesis is the development of new methods for controlling strain behavior and its applications toward novel semiconduc- tor/superconductor heterostructures based on nanomembranes. More specifically, the goal is to integrate inherently strained semiconductor layer structures with superconducting materials to create innovative electronic devices by the controlled releasing and rearrangement of thin films. By rolling up pre-patterned semiconductor/superconductor layers, device geometries have been realized that are not feasible using any other technique. In this way, superconducting hybrid junctions, or Josephson junctions, have been created and their basic properties investigated. The Josephson effect, and junctions displaying this quantum coherent behavior, have found many essential uses in diverse areas of science and technology. Many research groups around the world are involved in finding new materials and fabrication methods to tune the properties and structure of such Josephson devices further[11]. The inclusion of semi- conductors, for example, allows for a greater control of the charge carrier density within the junction area, thus allowing for "transistor-like" behavior in these superconducting devices. By rolling up the superconductor contacts using a strained semiconductor as scaffolding, the fabrication of hybrid nano-junctions is simplified drastically, removing the need for complicated processing steps such as electron-beam or nano-imprint lithography. Furthermore, the technique allows many nanometer-sized devices to be created in parallel on a single chip which has the advantage that it can be scaled up to full-wafer processing. First, post-growth processing techniques of epitaxial layers are developed in order to extend the control of hybrid device fabrication. Here, three unique concepts for controlling the rolling behavior of strained semiconductor nanomembranes are presented. First an optical method for inhibiting the rolling of the strained layers is described. Next, a selective etching method for destroying the inherent strain within the semiconductor layer is introduced. Finally, a method by which the strain gradient across a trilayer stack is altered in situ during rolling is presented. Next, the fabrication of a hybrid nanomembrane-based superconducting device is presented. Various experimental details of the fabrication process are analyzed, and the electronic properties of the completed device are investigated. The devices created here highlight the fabrication process in which nanometer-sized structures are created using self-assembly techniques and standard microelectronics fabrication methods, presenting a new method to circumvent more complicated processing techniques. References [1] G. M. Whitesides and B. Grzybowski. Self-assembly at all scales. Science 295, 2418{2421 (2002). [2] Y. G. Sun, W. M. Choi, H. Q. Jiang, Y. G. Y. Huang and J. A. Rogers. Controlled buckling of semiconductor nanoribbons for stretchable electronics. Nature Nanotechnology 1, 201{207 (2006). [3] O. G. Schmidt and K. Eberl. Nanotechnology - Thin solid films roll up into nanotubes. Nature 410, 168 (2001). [4] O. G. Schmidt, C. Deneke, Y. Nakamura, R. Zapf-Gottwick, C. Mller and N. Y. Jin-Phillipp. Nanotechnology { Bottom-up meets top-down. Advanced Solid State Physics 42, 231 (2002). [5] V. Ya. Prinz, V. A. Seleznev, A. K. Gutakovsky, A. V. Chehovskiy, V. V. Preobrazhenskii, M. A. Putyato and T. A. Gavrilova. Free-standing and overgrown InGaAs/GaAs nanotubes, nanohelices and their arrays. Physica E 6, 828 (2000). [6] D. J. Thurmer, C. Deneke, Y. F. Mei and O. G. Schmidt. Process integration of microtubes for uidic applications. Applied Physics Letters 89, 223507 (2006). [7] R. Songmuang, A. Rastelli, S. Mendach and O. G. Schmidt. SiOx/Si radial superlattices and microtube optical ring resonators. Applied Physics Letters 90, 091905 (2007). [8] E. J. Smith, Z. W. Liu, Y. F. Mei and O. G. Schmidt. Combined surface plasmon and classical waveguiding through metamaterial fiber design. Nano Letters 10, 1{5 (2010). [9] G. S. Huang, Y. F. Mei, D. J. Thurmer, E. Coric and O. G. Schmidt. Rolled-up transparent microtubes as two-dimensionally confined culture scaffolds of individual yeast cells. Lab on a Chip 9, 263{268 (2009). [10] C. C. B. Bufon, J. D. C. Gonzalez, D. J. Thurmer, D. Grimm, M. Bauer and O. G. Schmidt. Self-assembled ultra-compact energy storage elements based on hybrid nanomembranes. Nano Letters 10, 2506{2510 (2010). [11] G. Katsaros, P. Spathis, M. Stoffel, F. Fournel, M. Mongillo, V. Bouchiat, F. Lefloch, A. Rastelli, O. G. Schmidt and S. De Franceschi. Hybrid superconductor-semiconductor devices made from self-assembled SiGe nanocrystals on silicon. Nature Nanotechnology 5, 458{464 (2010). [12] Y. J. Doh, J. A. van Dam, A. L. Roest, E. P. A. M. Bakkers, L. P. Kouwenhoven and S. De Franceschi. Tunable supercurrent through semiconductor nanowires. Science 309, 272{275 (2005). [13] F. Giazotto, T. T. Heikkila, G. P. Pepe, P. Helisto, A. Luukanen and J. P. Pekola. Ultrasensitive proximity Josephson sensor with kinetic inductance readout. Applied Physics Letters 92, 162507 (2008). [14] S. P. Benz. Superconductor-normal-superconductor junctions for programmable voltage standards. Applied Physics Letters 67, 2714{2716 (1995). [15] Y. C. Tao and J. G. Hu. Superconducting spintronics: Spin-polarized transport in superconducting junctions with ferromagnetic semiconducting contact. Journal of Applied Physics 107, 041101 (2010).

Optoplasmonic microtube cavities, the combination of dielectric microcavities and noble metal layers, allow for the interactions between photonic modes and surface plasmons, leading to several novel phenomena and promising applications. In this thesis, the hybrid modes with different plasmon-types of evanescent field in the optoplasmonic microtube cavities are discussed. The basic physical mechanism for the generation of plasmon-type field is comprehensively investigated based on an effective potential approach. In particular, when the cavity wall becomes ultra-thin, the plasmon-type field can be greatly enhanced, and the hybrid modes are identified as strong photon-plasmon hybrid modes which are experimentally demonstrated in the metal-coated rolled-up microtube cavities. By designing a metal nanocap onto microtube cavities, angle-dependent tuning of hybrid photon-plasmon modes are realized, in which TE and TM polarized modes exhibit inverse tuning trends due to the polarization match/mismatch. And a novel sensing scheme is proposed relying on the intensity ratio change of TE and TM modes instead of conventionally used mode shift. In addition, localized surface plasmon resonances coupled to resonant light is explored by designing a vertical metal nanogap on microtube cavities. Selective coupling of high-order axial modes is demonstrated depending on spatial-location of the metal nanogap. A modified quasi-potential well model based on perturbation theory is developed to explain the selective coupling mechanism. These researches systematically explore the design of optoplasmonic microtube cavities and the mechanism of photon-plasmon coupling therein, which provide a novel platform for the study of both fundamental and applied physics such as the enhanced light-matter interactions and label-free sensing.

The combination of modern self-assembly techniques with well-established top-down processing methods pioneered in the electronics industry is paving the way for increasingly sophisticated devices in the future[1]. Nanomembranes, made from a variety of materials, can provide the necessary framework for a diverse range of device structures incorporating wrinkling, buckling, folding, and rolling of thin films[2, 3]. Over the past decade, an elegant symbiosis of bottom-up and top-down methods has been developed, allowing the fabrica- tion of hybrid layer systems via the controlled release and rearrangement of inherently strained layers [4]. Self-assembled rolled-up structures[4, 5] have become increasingly at- tractive in a number of fields including micro/nano uidics[6], optics[7](including metama- terial optical fibers[8]), Lab on a Chip applications[9], and micro- and nanoelectronics[10]. The use of such structures for microelectronic applications has been driven by the versatility in contacting geometries and the abundance of material combinations that these devices offer. By allowing devices to expand in the third dimension, certain obstacles that inhibit 2D structuring can be overcome in elegant ways. Similarly, recent progress in nanostructured superconducting electronic structures has been receiving increased attention[11]. The advancement of such devices has been mo- tivated by their use in quantum computation[12], high sensitivity radiation sensors[13], precision voltage standards[14] and superconducting spintronics[15] to name a few. Combining semiconductor with superconductor materials to create new hybrid geometries is advantageous because it adds the functionalities of the semiconductor, including high charge carrier mobilities, gating possibilities, and refined processing technologies. The main focus of the work presented in this thesis is the development of new methods for controlling strain behavior and its applications toward novel semiconduc- tor/superconductor heterostructures based on nanomembranes. More specifically, the goal is to integrate inherently strained semiconductor layer structures with superconducting materials to create innovative electronic devices by the controlled releasing and rearrangement of thin films. By rolling up pre-patterned semiconductor/superconductor layers, device geometries have been realized that are not feasible using any other technique. In this way, superconducting hybrid junctions, or Josephson junctions, have been created and their basic properties investigated. The Josephson effect, and junctions displaying this quantum coherent behavior, have found many essential uses in diverse areas of science and technology. Many research groups around the world are involved in finding new materials and fabrication methods to tune the properties and structure of such Josephson devices further[11]. The inclusion of semi- conductors, for example, allows for a greater control of the charge carrier density within the junction area, thus allowing for "transistor-like" behavior in these superconducting devices. By rolling up the superconductor contacts using a strained semiconductor as scaffolding, the fabrication of hybrid nano-junctions is simplified drastically, removing the need for complicated processing steps such as electron-beam or nano-imprint lithography. Furthermore, the technique allows many nanometer-sized devices to be created in parallel on a single chip which has the advantage that it can be scaled up to full-wafer processing. First, post-growth processing techniques of epitaxial layers are developed in order to extend the control of hybrid device fabrication. Here, three unique concepts for controlling the rolling behavior of strained semiconductor nanomembranes are presented. First an optical method for inhibiting the rolling of the strained layers is described. Next, a selective etching method for destroying the inherent strain within the semiconductor layer is introduced. Finally, a method by which the strain gradient across a trilayer stack is altered in situ during rolling is presented. Next, the fabrication of a hybrid nanomembrane-based superconducting device is presented. Various experimental details of the fabrication process are analyzed, and the electronic properties of the completed device are investigated. The devices created here highlight the fabrication process in which nanometer-sized structures are created using self-assembly techniques and standard microelectronics fabrication methods, presenting a new method to circumvent more complicated processing techniques. References [1] G. M. Whitesides and B. Grzybowski. Self-assembly at all scales. Science 295, 2418{2421 (2002). [2] Y. G. Sun, W. M. Choi, H. Q. Jiang, Y. G. Y. Huang and J. A. Rogers. Controlled buckling of semiconductor nanoribbons for stretchable electronics. Nature Nanotechnology 1, 201{207 (2006). [3] O. G. Schmidt and K. Eberl. Nanotechnology - Thin solid films roll up into nanotubes. Nature 410, 168 (2001). [4] O. G. Schmidt, C. Deneke, Y. Nakamura, R. Zapf-Gottwick, C. Mller and N. Y. Jin-Phillipp. Nanotechnology { Bottom-up meets top-down. Advanced Solid State Physics 42, 231 (2002). [5] V. Ya. Prinz, V. A. Seleznev, A. K. Gutakovsky, A. V. Chehovskiy, V. V. Preobrazhenskii, M. A. Putyato and T. A. Gavrilova. Free-standing and overgrown InGaAs/GaAs nanotubes, nanohelices and their arrays. Physica E 6, 828 (2000). [6] D. J. Thurmer, C. Deneke, Y. F. Mei and O. G. Schmidt. Process integration of microtubes for uidic applications. Applied Physics Letters 89, 223507 (2006). [7] R. Songmuang, A. Rastelli, S. Mendach and O. G. Schmidt. SiOx/Si radial superlattices and microtube optical ring resonators. Applied Physics Letters 90, 091905 (2007). [8] E. J. Smith, Z. W. Liu, Y. F. Mei and O. G. Schmidt. Combined surface plasmon and classical waveguiding through metamaterial fiber design. Nano Letters 10, 1{5 (2010). [9] G. S. Huang, Y. F. Mei, D. J. Thurmer, E. Coric and O. G. Schmidt. Rolled-up transparent microtubes as two-dimensionally confined culture scaffolds of individual yeast cells. Lab on a Chip 9, 263{268 (2009). [10] C. C. B. Bufon, J. D. C. Gonzalez, D. J. Thurmer, D. Grimm, M. Bauer and O. G. Schmidt. Self-assembled ultra-compact energy storage elements based on hybrid nanomembranes. Nano Letters 10, 2506{2510 (2010). [11] G. Katsaros, P. Spathis, M. Stoffel, F. Fournel, M. Mongillo, V. Bouchiat, F. Lefloch, A. Rastelli, O. G. Schmidt and S. De Franceschi. Hybrid superconductor-semiconductor devices made from self-assembled SiGe nanocrystals on silicon. Nature Nanotechnology 5, 458{464 (2010). [12] Y. J. Doh, J. A. van Dam, A. L. Roest, E. P. A. M. Bakkers, L. P. Kouwenhoven and S. De Franceschi. Tunable supercurrent through semiconductor nanowires. Science 309, 272{275 (2005). [13] F. Giazotto, T. T. Heikkila, G. P. Pepe, P. Helisto, A. Luukanen and J. P. Pekola. Ultrasensitive proximity Josephson sensor with kinetic inductance readout. Applied Physics Letters 92, 162507 (2008). [14] S. P. Benz. Superconductor-normal-superconductor junctions for programmable voltage standards. Applied Physics Letters 67, 2714{2716 (1995). [15] Y. C. Tao and J. G. Hu. Superconducting spintronics: Spin-polarized transport in superconducting junctions with ferromagnetic semiconducting contact. Journal of Applied Physics 107, 041101 (2010).

Over the past two decades, organic semiconductors played a growing part as active layers in several electronic systems such as sensors, field‑effect transistors or light emitting diodes to cite a few. In fact, organic materials offer a high versatility and flexibility. However, pure organic systems often lack stability and robustness, which can be overcome by combining them with inorganic scaffolds. In this work, a conducting polymer, polypyrrole (PPy) is employed to create new sensor elements based on the combination of both inorganic and organic layers. Electrical measurements, infrared spectroscopy and current sensing atomic force microscopy provides a better understanding of the polymer behavior upon immersion in aqueous solutions. The observed discharge in water leads to a straightforward application of the device as an in‑flow sensor for several acids like HCl, H2SO4 and H3PO4. The wide range of sensing concentrations as well as the low detection limit place the present detector among the best reported so far in the literature. In a further step to turn towards lab‑in‑a‑tube devices, tubular‑shaped‑integrated microelectrodes are developed by using the rolled‑up technology. As a proof of concept, the successful integration of PPy as an active layer and its use as a gas sensor for volatile organic compounds (VOCs) is demonstrated. Finally, by adapting the rolled‑up top electrodes, as developed by Bof Bufon et al. for self‑assembled monolayers (SAMs), thin PPy films (<50 nm) are vertically contacted and their electrical characteristics measured as a function of temperature and electric field. From the transport investigations, it is observed that an insulating‑to‑metallic transition occurs in the polymeric film by increasing the bias voltage. Other molecular layers like CuPc can be incorporated in these platforms, opening the way towards emerging organic devices.