Optical signatures of charge- and energy transfer in TMDC/TMDC and TMDC/perovskite heterostructures

Heterostructures (HSs) based on two-dimensional transition metal dichalcogenides (TMDCs) are highly intriguing materials because of the layers’ pronounced excitonic properties and their nontrivial contributions to the HS. These HSs exhibit unique properties that are not observed in either of the constituent components in isolation. Interlayer...

Charge Transfer and Asymmetric Coupling of MoSe₂ Valleys to the Magnetic Order of CrSBr

van der Waals heterostructures composed of two-dimensional (2D) transition metal dichalcogenides and vdW magnetic materials offer an intriguing platform to functionalize valley and excitonic properties in nonmagnetic TMDs. Here, we report magneto photoluminescence (PL) investigations of monolayer (ML) MoSe₂ on the layered A-type...

Advances in Modeling of Noisy Quantum Computers: Spin Qubits in Semiconductor Quantum Dots

The new quantum era is expected to have an unprecedented social impact, enabling the research of tomorrow in several pivotal fields. These perspectives require a physical system able to encode, process and store for a sufficiently long amount of time the quantum information. However, the optimal engineering of currently available quantum...

Three-Dimensional Atomic-Scale Tomography of Buried Semiconductor Heterointerfaces

Atom probes generate three-dimensional atomic-scale tomographies of material volumes corresponding to the size of modern-day solid-state devices. Here, the capabilities of atom probe tomography are evaluated to analyze buried interfaces in semiconductor heterostructures relevant for electronic and quantum devices. Employing brute-force search...

Room temperature ppt-level NO₂ gas sensor based on SnO _x/SnS nanostructures with rich oxygen vacancies

In this paper, tin oxidation (SnO x )/tin-sulfide (SnS) heterostructures are synthesized by the post-oxidation of liquid-phase exfoliated SnS nanosheets in air. We comparatively analyzed the NO2 gas response of samples with different oxidation levels to study the gas sensing mechanisms. The results show that the samples oxidized at 325 °C are...

Metal sulfides for gas sensing applications: devices and mechanisms

Nanostructured materials have attracted more and more attention in the applications of gas sensing due to their high specific surface area, numerous surface-active sites, as well as the effect of crystal facets with high surface reactivity. These kinds of gas sensors are mainly used for detecting air quality, environment situation, and breath...

Toward BaSi₂/Si Heterojunction Thin-Film Solar Cells: Insights into Heterointerface Investigation, Barium Depletion, and Silicide-Mediated Silicon Crystallization

The knowledge of the structural and compositional details of Si/BaSi₂/Si heterostructure annealed at high temperature is a prerequisite for BaSi₂ application in heterojunction thin-film solar cells. For this purpose, Si/BaSi₂/Si heterostructures deposited by magnetron sputtering with different Si layer...

Mesoscopic transport in 2D materials and heterostructures

This thesis presents an experimental work on electronic transport in two-dimensional (2D) van der Waals systems. The variety of the physics of the chapters reflects the exploratory character of the Ph.D. study and demonstrates the versatility and the unique properties of some of the members of the vast group of van der Waals materials. In the...

Spin–orbit coupling and geometric phases at oxide interfaces

In this work, we investigate electronic and magnetic phenomena in thin films and heterostructures of transition metal oxides with strong spin–orbit coupling. Ultrathin films are prepared by pulsed laser deposition, a technique which enables layer-by-layer growth of complex materials on atomically flat crystal surfaces. The properties of these...

Designing a hybrid thin-film/wafer silicon triple photovoltaic junction for solar water splitting

Solar fuels are a promising way to store solar energy seasonally. This paper proposes an earth-abundant heterostructure to split water using a photovoltaic-electrochemical device (PV-EC). The heterostructure is based on a hybrid architecture of a thin-film (TF) silicon tandem on top of a c-Si wafer (W) heterojunction solar cell (a-Si:H (TF)...

Light control of the nanoscale phase separation in heteroepitaxial nickelates

Strongly correlated materials show unique solid-state phase transitions with rich nanoscale phenomenology that can be controlled by external stimuli. Particularly interesting is the case of light–matter interaction in the proximity of the metal–insulator transition of heteroepitaxial nickelates. In this work, we use near-infrared laser light in...

Metal–Insulator Transitions in Heterostructures of Quantum Materials

This thesis is an experimental investigation of the physical properties of different transition metal oxide ultra-thin films. A common feature of these various materials and structures is that they exhibit a solid-state phase transition from a metallic to an insulating state, which is triggered upon changing sample composition, or by varying an...

Nanoscale Electrostatic Control of Superconducting Oxide Interfaces

Side Gate Tunable Josephson Junctions at the LaAlO₃/SrTiO₃ Interface

Novel physical phenomena arising at the interface of complex oxide heterostructures offer exciting opportunities for the development of future electronic devices. Using the prototypical LaAlO₃/SrTiO₃ interface as a model system, we employ a single-step lithographic process to realize gate-tunable Josephson junctions...

Tuning the Lattice Parameter of In_xZn_yP for Highly Luminescent Lattice-Matched Core/Shell Quantum Dots

Colloidal quantum dots (QDs) show great promise as LED phosphors due to their tunable narrow-band emission and ability to produce high-quality white light. Currently, the most suitable QDs for lighting applications are based on cadmium, which presents a toxicity problem for consumer applications. The most promising cadmium-free candidate QDs...

Effects of the electrostatic environment on the Majorana nanowire devices

One of the promising platforms for creating Majorana bound states is a hybrid nanostructure consisting of a semiconducting nanowire covered by a superconductor.Weanalyze the previously disregarded role of electrostatic interaction in these devices. Our main result is that Coulomb interaction causes the chemical potential to respond to an applied...

Non-equilibrium electron transport in mesoscale superconducting hybrids

This thesis focusses on driven superconducting heterostructures. Both experimentally and theoretically we address the following questions: (a) how does the presence of different metallic and dielectric materials influence the electronic properties of a driven superconductor? (b) how does a non-equilibrium electron distribution arise and how does...