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This thesis focuses on the guided self-assembly of metastable nanomembranes (NMs) that are either amorphous or polycrystalline. Guided self-assembly of NMs is a robust and scalable method to obtain a variety of three-dimensional structures such as helices, rolled-up tubes, and networks of interconnected channels. These 3D structures have important applications as on-chip actuators, sensors, inductors, transformers, waveguides, and antennas. Furthermore, a large amount of strain and strain gradient can be imparted in NMs by bending them to a nanoscale and microscale radius of curvature, making guided self-assembly on NMs a viable route to extreme strain engineering of amorphous and polycrystalline NMs. Leveraging the tremendous potential of self-assembled NMs requires precise predictive control of their geometrical attributes, such as the diameter of rolled-up tubes, the diameter and pitch of helical structures, and the cross-sectional area of wrinkled channels. The last 20 years have shown much progress in controlling the self-assembly of single-crystalline and stable films, such as semiconductors. Nevertheless, there is a limited understanding of the relaxation of metastable amorphous and polycrystalline NMs. This work aims at filling this knowledge gap by a multidisciplinary approach that encompasses synthesis and processing of NMs, continuum mechanics modeling, and characterization of the structural and functional properties of the NMs. Central to this effort is predictive modeling of the mechanical response of amorphous and polycrystalline NMs upon relaxation of residual stress in the deposited layers and any additional stress arising from the reconfiguration of atomic bonds under an externally applied stimulus, such as heat. The thesis describes the application of the model to two selected case studies and systems, namely complex oxide and metal NMs. After heating, reconfiguration-driven assembly is observed in strontium titanate (STO) a

Monolithic semiconductor lasers including edge-emitting lasers (EELs) and vertical-cavity surface-emitting lasers (VCSELs) fail to realize simultaneous achievement of both high-power high-quality beams due to intrinsic limitations of their resonant cavity. Photonic crystal surface emitting lasers (PCSELs) address these structural limitations through employment of a two-dimensional photonic crystal (PC) cavity that creates feedback at a single wavelength for laterally scalable devices. This function of the PC allows PCSELs to power scale with area while maintaining single-mode emission required for diffraction-limited beams. In this way, PCSELs fulfill an industry demand for high-power high-quality lasing from a single chip. Early PCSELs were fabricated by way of wafer fusion where two wafers, the first containing the active layer and the second containing the PC, are joined together via heat treatment in a liquid phase epitaxy furnace. This technique produces a high density of light absorbing defects at the bonded interface. Modern PCSEL fabrication forgoes wafer bonding in favor of processes that maintain crystalline order throughout the entire structure. This work demonstrates PCSEL fabrication by epitaxial regrowth and single- epitaxy methods to illustrate their respective advantages and engineering challenges. While specific properties of epitaxial regrowth are beneficial for total output power, a single-epitaxy process simplifies fabrication and provides a more scalable and wavelength versatile platform. PCSELs with InGaAs multiple-quantum-well (MQW) active regions are constructed by molecular beam epitaxy (MBE) using both regrowth and single-epitaxy methods. Total output power of epitaxially regrown PCSELs is dramatically improved by implementation of a flip-chip bonding process and a metal- organic chemical vapor deposition (MOCVD) regrowth step. By affecting stable large- area coherent lasing, the fabricated PCSELs described in this work address th

Surface acoustic wave devices have not yet achieved their full potential as the effects of standing acoustic fields on stress-sensitive phenomena in semiconductor systems have been largely unexplored. From this perspective, it is necessary to develop novel methods to characterize surface acoustic wave devices quantitatively and prepare an experimental platform to probe stress-enhanced processes. In this dissertation, interdigitated transducer devices are fabricated on gallium arsenide to evaluate their potential impact on strain-enhanced phenomena. A novel Raman characterization technique characterizes the surface stress induced by a standing acoustic field, revealing stress values on the order of 108 Pa. FEM software models the electrical and mechanical behaviors of interdigitated transducer structures, and the simulated displacements are confirmed with atomic force microscopy at room temperatures. FEM modeling predicts device performance for temperatures as high as 177 °C, confirming that SAW devices are a robust experimental platform for studying strain-enhanced phenomena. A full-geometry parametric study suggests potential avenues to optimize SAW-resonator designs and produce intricate and powerful stress fields, which can then sculpt designer features for quantum devices via stress-enhanced atomic diffusion.

Filamentation in air is a phenomenon that has been extensively investigated for the last two decades. At sufficiently high intensity, even air is a nonlinear medium. These intensities are reached with ultrashort pulses (50 to 100 fs) of more than 1 J energy, which self-focus in air, reach ionizing intensities of oxygen and nitrogen, creating a plasma that defocuses the beam. The air filament is a self-induced waveguide resulting from a balance of focusing and defocusing. In this work new techniques were developed to visualize and analyze this phenomenon through its emission, in particu- lar the UV emission of the nitrogen cation. Contrary to popular belief, this emission does not proceed to be instantaneous upon ionization of nitrogen, but is delayed by tens of ps with respect to the ionizing/propagating short pulse. The time resolved emission of the nitrogen cation is very complex and was analyzed through pump- probe spectroscopy, the pump being the filamenting pulse at 800nm, and the probe its second harmonic. It was found that the medium within the filament volume provided transient optical amplification at the wavelengths of the rotational-vibrational lines of N2+ . The temporal behavior of the gain itself is complex, since it repeats itself at fixed time intervals (“revival times”). The wavelength of these lines is also time dependent, because they are Stark shifted in the expanding plasma. This study suggests that the filament creates a “laser in the sky”, which could be invaluable in amplifying weak return signals in remote sensing.

Filamentation in air is a phenomenon that has been extensively investigated for the last two decades. At sufficiently high intensity, even air is a nonlinear medium. These intensities are reached with ultrashort pulses (50 to 100 fs) of more than 1 J energy, which self-focus in air, reach ionizing intensities of oxygen and nitrogen, creating a plasma that defocuses the beam. The air filament is a self-induced waveguide resulting from a balance of focusing and defocusing. In this work new techniques were developed to visualize and analyze this phenomenon through its emission, in particu- lar the UV emission of the nitrogen cation. Contrary to popular belief, this emission does not proceed to be instantaneous upon ionization of nitrogen, but is delayed by tens of ps with respect to the ionizing/propagating short pulse. The time resolved emission of the nitrogen cation is very complex and was analyzed through pump- probe spectroscopy, the pump being the filamenting pulse at 800nm, and the probe its second harmonic. It was found that the medium within the filament volume provided transient optical amplification at the wavelengths of the rotational-vibrational lines of N2+ . The temporal behavior of the gain itself is complex, since it repeats itself at fixed time intervals (“revival times”). The wavelength of these lines is also time dependent, because they are Stark shifted in the expanding plasma. This study suggests that the filament creates a “laser in the sky”, which could be invaluable in amplifying weak return signals in remote sensing.

This dissertation describes the development of an all solid-state optical cryo-cooler. Crystals of 10% wt. ytterbium-doped yttrium lithium fluoride (Yb3+:YLF) are used to cool an infrared HgCdTe sensor payload to an absolute temperature below 135 K, equivalent to delta T equal 138 K below ambient. This record level of cooling is accomplished with a single stage, in a completely vibration-free environment, with a corresponding cooling power of 190 mW. This milestone is made possible by the design and fabrication of an undoped YLF thermal link that efficiently shields the payload with a non-right angle kink from intense anti-Stokes fluorescence while withstanding frequent thermal cycling. We also describe the design and implementation of novel MgF2 and sapphire thermal links that promise sub-100 K payload temperatures. This investigation considers thermal link materials that are CTE (Coefficients of Thermal Expansion) matched to YLF crystal and includes rigorous optical and thermal modeling with various geometries.

This dissertation describes the development of an all solid-state optical cryo-cooler. Crystals of 10% wt. ytterbium-doped yttrium lithium fluoride (Yb3+:YLF) are used to cool an infrared HgCdTe sensor payload to an absolute temperature below 135 K, equivalent to delta T equal 138 K below ambient. This record level of cooling is accomplished with a single stage, in a completely vibration-free environment, with a corresponding cooling power of 190 mW. This milestone is made possible by the design and fabrication of an undoped YLF thermal link that efficiently shields the payload with a non-right angle kink from intense anti-Stokes fluorescence while withstanding frequent thermal cycling. We also describe the design and implementation of novel MgF2 and sapphire thermal links that promise sub-100 K payload temperatures. This investigation considers thermal link materials that are CTE (Coefficients of Thermal Expansion) matched to YLF crystal and includes rigorous optical and thermal modeling with various geometries.

GaSb based photovoltaic devices have been demonstrated on recombination in dislocation centers is a dominant loss mechanism in GaSb solar cell grown on GaAs substrate. Also, the band offset between AlSb/GaSb is not proper for photovoltaic application and block the photogenerated carrier to reach a contact. InGaSb strained layer was chosen as replacement of AlSb defect filtering layer. Effect of strain, thickness, and a number of InGaSb defec

This work modeled the early to middle successes achieved in the field of ultrafast, high peak power optics, beginning with the work of Nobel Prize winners Donna Strickland and Gérard Mourou in 1985. In our work, 100 fs light pulses of around 800 nm were generated by a Ti:Sapphire oscillator, then amplified to approximately 30 GW peak power using a chirped pulse amplification system that included regenerative and multi-pass amplifiers. As a verification of our pulses having high peak powers and ultrashort durations, they were then used to strike water, glass, and a Kerr Cell. Supercontinuum generation was observed as a result of striking the water and the glass. Moreover, using water produced a stable source of white light. Glass did not produce a stable source of white light due to material damage. In striking the Kerr Cell, we hoped to observe an induced voltage from the interaction of high power pulses with the CS2 contained within. This was not observed. However, spectral components of green, yellow, and red were observed. In addition to the expected results, for several months during the experiment we generated 55 fs pulses. This is an exciting result as pulses of this duration are thought by some to be impossible given the elements used for our system. The precise mechanisms that contributed to the sub-100 fs pulses are yet undetermined. This suggests interesting work for the future of this system given the extra stability it affords as compared to other modern systems.

GaSb based photovoltaic devices have been demonstrated on recombination in dislocation centers is a dominant loss mechanism in GaSb solar cell grown on GaAs substrate. Also, the band offset between AlSb/GaSb is not proper for photovoltaic application and block the photogenerated carrier to reach a contact. InGaSb strained layer was chosen as replacement of AlSb defect filtering layer. Effect of strain, thickness, and a number of InGaSb defec

This work modeled the early to middle successes achieved in the field of ultrafast, high peak power optics, beginning with the work of Nobel Prize winners Donna Strickland and Gérard Mourou in 1985. In our work, 100 fs light pulses of around 800 nm were generated by a Ti:Sapphire oscillator, then amplified to approximately 30 GW peak power using a chirped pulse amplification system that included regenerative and multi-pass amplifiers. As a verification of our pulses having high peak powers and ultrashort durations, they were then used to strike water, glass, and a Kerr Cell. Supercontinuum generation was observed as a result of striking the water and the glass. Moreover, using water produced a stable source of white light. Glass did not produce a stable source of white light due to material damage. In striking the Kerr Cell, we hoped to observe an induced voltage from the interaction of high power pulses with the CS2 contained within. This was not observed. However, spectral components of green, yellow, and red were observed. In addition to the expected results, for several months during the experiment we generated 55 fs pulses. This is an exciting result as pulses of this duration are thought by some to be impossible given the elements used for our system. The precise mechanisms that contributed to the sub-100 fs pulses are yet undetermined. This suggests interesting work for the future of this system given the extra stability it affords as compared to other modern systems.

Nanoscale transport using the kinesin-microtubule (MT) biomolecular system has been successfully used in a wide range of nanotechnological applications including self-assembly, nanofluidic transport, and biosensing. Most of these applications use the ‘gliding motility geometry’, in which surface-adhered kinesin motors attach and propel MT filaments across the surface, a process driven by ATP hydrolysis. It has been demonstrated that active assembly facilitated by these biomolecular motors results in complex, non-equilibrium nanostructures currently unattainable through conventional self-assembly methods. In particular, MTs functionalized with biotin assemble into rings and spools upon introduction of streptavidin and/or streptavidin-coated nanoparticles. Upon closer examination of these structures using fluorescence and electron microscopy, the structures revealed a level of irregularity including kinked and coiled domains, as well as in- and out- of -plane loops. In this work, we describe the effects of large scale “defective” segments (i.e. non-biotinylated MTs) on active assembly of nanocomposite spools. We demonstrate the preferential removal of the defective portions from spools during assembly to overcome structurally induced strain in regions that lack biotin-streptavidin bonds. Additionally, we show how the level of defective MTs affect the morphology and physical properties of the resulting nanostructures.Further, we explore alternative nanostructures for controlling transport using the kinesin-MT biomolecular system. Guiding MT transport has been achieved using lithographically patterning physical and chemical features, which have been shown to limit the MT trajectories, causing MTs to escape the barriers and lead to stalling or complete loss of MTs. Here, we demonstrate reliable guiding and transport of MTs on three different chemically modified, and structurally varying surfaces using 1) self-assembled monolayers (SAMs) with varying functional groups

Plasmonic modes in metal nanostructures enable light confinement at subwavelength scales. This field confinement is important for exploring the potential of nanotechnology in miniaturization of optics as well as for the advancement of optoelectronic devices, such as photodetectors, photovoltaics, and light-emitting diodes. Plasmon resonances are also ideal for developing ultrasensitive biosensors, and for enhancing surface photochemistry and photocatalysis. The increasing number of plasmon applications requires fundamental understanding of the plasmon coupled system which has not yet been completely understood. Controlling and engineering the plasmon response at the nanoscale will open still more applications in material science, communications, biochemistry and medicine. In this dissertation, the optical interactions between resonant plasmonic nanoparticles and both polarizable semiconductor substrates and metallic films have been investigated by analyzing the scattering properties of the plasmonic nanoparticles and the photoluminescence (PL) of emitters embedded in the semiconductor substrate. Fundamental studies of the coupling of the localized surface plasmon resonance of colloidal gold nanoparticles with III-V semiconductor quantum dots (QDs), and metallic gold-films have been carried out. By coupling colloidal gold nanorods (AuNRs) to InAs QDs, embedded in InGaAs/GaAs quantum well, plasmon enhanced carrier generation and photon emission are investigated by monitoring the PL intensity enhancement at room temperature. The length scales of the near-field confinement, carrier diffusion, and excitation energy transfer to the metal surface (that leads to quenching of PL at small AuNR-InAs separation distances), have been determined systematically both experimentally and theoretically by varying the GaAs capping layer thickness. After establishing the dependence on separation, the temperature dependence of plasmon enhanced carrier generation and photon emis

Plasmonic modes in metal nanostructures enable light confinement at subwavelength scales. This field confinement is important for exploring the potential of nanotechnology in miniaturization of optics as well as for the advancement of optoelectronic devices, such as photodetectors, photovoltaics, and light-emitting diodes. Plasmon resonances are also ideal for developing ultrasensitive biosensors, and for enhancing surface photochemistry and photocatalysis. The increasing number of plasmon applications requires fundamental understanding of the plasmon coupled system which has not yet been completely understood. Controlling and engineering the plasmon response at the nanoscale will open still more applications in material science, communications, biochemistry and medicine. In this dissertation, the optical interactions between resonant plasmonic nanoparticles and both polarizable semiconductor substrates and metallic films have been investigated by analyzing the scattering properties of the plasmonic nanoparticles and the photoluminescence (PL) of emitters embedded in the semiconductor substrate. Fundamental studies of the coupling of the localized surface plasmon resonance of colloidal gold nanoparticles with III-V semiconductor quantum dots (QDs), and metallic gold-films have been carried out. By coupling colloidal gold nanorods (AuNRs) to InAs QDs, embedded in InGaAs/GaAs quantum well, plasmon enhanced carrier generation and photon emission are investigated by monitoring the PL intensity enhancement at room temperature. The length scales of the near-field confinement, carrier diffusion, and excitation energy transfer to the metal surface (that leads to quenching of PL at small AuNR-InAs separation distances), have been determined systematically both experimentally and theoretically by varying the GaAs capping layer thickness. After establishing the dependence on separation, the temperature dependence of plasmon enhanced carrier generation and photon emis

Study and prediction of classical and non-classical mechanical properties of GaN is crucial due to the potential application of GaN nanowires (NWs) in piezoelectric, probe-based nanometrology, and nanolithography areas. GaN is mainly grown on sapphire substrates whose lattice constant and thermal expansion coefficient are significantly different from GaN. These discrepancies cause mechanical defects and high residual stresses and strains in GaN, which reduce its quantum efficiency. Specifically, for nanoscale applications, the mechanical properties of materials differ significantly compared to the bulk properties due to size-effects. Therefore, it is essential to investigate the mechanical properties of GaN NWs using the non-classical solid mechanic theories, modified couple stress theory (MCST) and modified strain gradient theory (MSGT). Experimentally the GaN NWs were prepared by using top-down approach to etch c-plane GaN layer grown in Metal Organic Chemical Vapor Deposition (MOCVD) chamber to achieve high aspect ratio NWs with high uniformity. An Atomic Force Microscope (AFM) was used to apply an infinitesimal deflection on the top of clamped-free NWs while monitoring the lateral and normal forces. According to the MCST, the Young’s modulus, shear modulus and length scale were measured to be 323 GPa, 133 GPa and 13 nm, respectively, and according to the MSGT, they were measured to be 319 GPa, 132 GPa and 8 nm, respectively. Furthermore, a quantum mechanics based approached was conducted to estimate the classical and non-classical mechanical properties of the GaN NWs as well.

Metrology technologies are an essential adjunct to Integrated Circuit (I.C.) Semiconductor manufacturing. Scatterometry, an optical metrology, was chosen to measure 50 nm half pitch feature structures. A bread-board scatterometry system has been assembled to provide a non-contact, non-destructive, accurate and flexible measurement. A real-time, on-line scatterometry system has also been demonstrated and proven to provide a high throughput measurement. Three different types of samples have been measured using the scatterometry setup. The wire-grid polarizer (WGP) sample has been made by Jet and Flash Nanoimprint Lithography with ~100 nm pitch and ~50 nm wide ~200 nm tall Al gratings on fused silica substrates. One of the resist grating samples has been made by Roll-to-Roll Nanoimprint Lithography with ~130 nm pitch and ~65 nm wide ~100 nm tall resist gratings on polycarbonate substrate. The other resist grating samples have been made by Immersion Interference Lithography with ~80 nm pitch and ~70 nm tall resist gratings on silicon substrate. For the WGP, four wavelengths (244 nm, 405 nm, 633 nm and 982 nm) were used to study the dependence of the parametric scatterometry on a function of the wavelength to sample pitch ratio ( /p: from 2.4 to 9.8). Results show that even for a laser wavelength ten times larger than the sample pitch, scatterometry can still provide the characteristic structure information. The definition of the grating structure in the simulation has improved from a simple trapezoidal structure to a more complicated model with top rounding structure and an Al2O3 “skin”. With a better model and definition of the structure, simulation results have been closer to measurement results for all four wavelengths and the parameter sets present a very close results from scatterometry measurements. For the resist grating samples, scatterometry has less sensitivity because of lower index contrast than WGP, but a 405

Metrology technologies are an essential adjunct to Integrated Circuit (I.C.) Semiconductor manufacturing. Scatterometry, an optical metrology, was chosen to measure 50 nm half pitch feature structures. A bread-board scatterometry system has been assembled to provide a non-contact, non-destructive, accurate and flexible measurement. A real-time, on-line scatterometry system has also been demonstrated and proven to provide a high throughput measurement. Three different types of samples have been measured using the scatterometry setup. The wire-grid polarizer (WGP) sample has been made by Jet and Flash Nanoimprint Lithography with ~100 nm pitch and ~50 nm wide ~200 nm tall Al gratings on fused silica substrates. One of the resist grating samples has been made by Roll-to-Roll Nanoimprint Lithography with ~130 nm pitch and ~65 nm wide ~100 nm tall resist gratings on polycarbonate substrate. The other resist grating samples have been made by Immersion Interference Lithography with ~80 nm pitch and ~70 nm tall resist gratings on silicon substrate. For the WGP, four wavelengths (244 nm, 405 nm, 633 nm and 982 nm) were used to study the dependence of the parametric scatterometry on a function of the wavelength to sample pitch ratio ( /p: from 2.4 to 9.8). Results show that even for a laser wavelength ten times larger than the sample pitch, scatterometry can still provide the characteristic structure information. The definition of the grating structure in the simulation has improved from a simple trapezoidal structure to a more complicated model with top rounding structure and an Al2O3 “skin”. With a better model and definition of the structure, simulation results have been closer to measurement results for all four wavelengths and the parameter sets present a very close results from scatterometry measurements. For the resist grating samples, scatterometry has less sensitivity because of lower index contrast than WGP, but a 405

Semiconductor membranes offer an interesting materials and device development platform due to their ability to integrate dissimilar materials through a print, stamp and transfer process. There is a lot of interest in integrating antimonide based type-II superlattices (T2SL) onto inexpensive substrates, such as Si, to not only undertake fundamental studies into the optical, electronic and structural properties of the superlattices but also to fabricate wafer-level infrared (IR) photodetectors. An effective approach to transfer type-II superlattice membranes (T2SL-M) onto alternate substrates is based on membrane release from the native GaSb substrate followed by the transfer to a new host substrate. In this work, I have transferred InAs/GaSb and InAs/InAsSb T2SLs with different in-plane geometries from a GaSb substrate to a variety of host substrates, including Si, polydimethylsiloxane and metal coated surfaces. Electron microscopy shows structural integrity of transferred membranes with thicknesses ranging from 100 nm to 2.5 µm and lateral sizes from 24x24 µm2 v to 1x1 cm2 . Atomic force and electron microscopy reveal the excellent quality of the membrane interface with the new host. The crystalline structure of the membrane is not altered by the fabrication process, and minimal elastic relaxation occurs during the release step, as demonstrated by X-ray diffraction and mechanical modeling. I have also used the antimonide superlattice membranes to realize wafer level infrared detectors on silicon substrates without using conventional Indium-bump hybridization. In this approach, PIN superlattices are grown on top of a 60 nm Al0.6Ga0.4Sb sacrificial layer on a GaSb host substrate. Following the growth, I have transferred the individual pixels using an epitaxial lift-off technique, which consists of a wet-etch to undercut the pixels followed by a dry-stamp process to transfer the pixels to a silicon substrate prepared with a gold layer. I have done structural and opt

Interfacing biological cells and solid-state devices is crucial in many applications, ranging from well-established fields, such as electrophisiology, to the newly developed areas of optogenetics and mechanobiology. Most biological cells are anchored to substrates with elastic modulus, E, in the range of ~1 to 100 kPa, the moduli of brain-tissue and osteoid, respectively. On the other hand, bulk semiconductor substrates have ~6 orders of magnitude higher elastic modulus. This large elastic mismatch between devices and cells natural microenvironments is an issue for bio-devices integration, as cells are highly sensitive to mechanical cues. Specifically, cells exert traction forces on their surroundings and adjust their adhesion mechanism, cytoskeleton, locomotion and overall state according to the stiffness of the substrate they are anchored to. This type of behavior makes it a significant challenge to integrate semiconductor devices with biological cells without altering the cell state. I demonstrate a new family of culture platforms to successfully integrate biological cells and electronic/photonic devices from a mechanical perspective. The proposed platforms are referred to as effectively compliant layered substrates (ECLS). ECLS are based on inorganic nanomembranes (NMs) partially suspended v or bonded to compliant substrates. The unique attribute of ECLS is that, the constitutive material of the NM provides the electrical and optical functionality necessary to a device operation, while the NM geometry and the nature of the supporting substrate can be tailored to match the mechanical response of biological tissues. Specifically, I present fabrication and bio-interfacing of ECLS comprising of device-grade, single-crystal Si NMs on a compliant PDMS substrate with tunable elastic modulus from ~kPa to ~MPa. NMs with thickness in the range of ~20-220 nm and ~ 1x1 cm2 lateral areas are used in this study. ECLS are obtained using a two-step process, including synthes