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Semiconductor nanowire lasers can produce guided coherent light emission with miniaturized geometry, bringing about new possibilities for a variety of applications including nanophotonic circuits, optical sensing, and on-chip and chip-to-chip optical communications. Here, we report on the realization of single-mode and room-temperature lasing from 890 to 990 nm, utilizing a novel design of single
The nanoscale is an exciting domain when it comes to crystal growth, light-matter interaction and electronics. Especially for optoelectronics, semiconductor nanostructures have many advantages compared to traditional planar structures and are highly interesting for the next generation of solar cells, photodetectors and light emitting diodes. This dissertation explores device fabrication, and elect
III-V semiconductor heterostructures are important components of many solid-state optoelectronic devices, but the ability to control and tune the electrical and optical properties of these structures in conventional device geometries is fundamentally limited by the bulk dimensionality and the inability to accommodate lattice-mismatched material combinations. Here we demonstrate how semiconductor n
Pt-TiO2-C composites with different titanium oxide loading were synthesized by photo-deposition and chemical vapor deposition methods. The changes in their electronic properties improve the electrochemical activity toward the oxygen reduction reaction (ORR) compared to the Pt-C catalyst synthesized at the same conditions. The platinum samples were physically characterized by means of Transmission
Second harmonic generation is analyzed from a microscopical point of view using a non-equilibrium Green's function formalism. Through this approach the complete on-state of the laser can be modeled and results are compared to experiment with good agreement. In addition, higher order current response is extracted from the calculations and together with waveguide properties, these currents provide t
Fundamental symmetries in thermoelectric quantum transport, beyond Onsagers relations, were predicted two decades ago but have to date not been observed in experiments. Recent works have predicted the symmetries to be sensitive to energy-dependent, inelastic scattering, raising the question whether they exist in practice. Here, we answer this question affirmatively by experimentally verifying the
We present the results of a quantum mechanical modelling of the free carrier absorption (FCA) in semiconductor heterolayers. Elastic and inelastic scatterers are considered with emphasis on the interface defects (optical phonons) contributions to the induced photon absorption for elastic (inelastic) scatterers. Various approaches to FCA are also presented (perturbation, Green's function technique)
This study sought to determine the prevalence of transactional sex among university students in Uganda and to assess the possible relationship between transactional sex and sexual coercion, physical violence, mental health, and alcohol use.
Objectives: To investigate whether low self-rated health (SRH) is associated with increased mortality in individuals with diabetes. Design: Population-based prospective cohort study. Setting: Enrolment took place between 1992 and 2000 in four centres (Bilthoven, Heidelberg, Potsdam, Umea) in a subcohort nested in the European Prospective Investigation into Cancer and Nutrition. Participants: 3257
The geometric and electronic structure of condensed phase organic conducting polymer PEDOT:PSS blends has been investigated by periodic density functional theory (DFT) calculations with a generalized-gradient approximation (GGA) functional, and a plane wave basis set. The influence of the degree of doping of the PEDOT polymer on structural and optical parameters such as the reflectivity, absorbanc
We report on the use of binary mixtures of oppositely charged gold nanoparticles (AuNPs) and spherical polyelectrolyte brushes (SPBs), consisting of a polystyrene core onto which long polystyrene sulfonate chains are grafted, as a simple model system to investigate the influence of directional interactions on self-assembly. We demonstrate that the mixing ratio, i.e., the number of AuNPs per SPB, h
Background: The expected reduction in cervical cancer incidence as a result of increased access to antiretroviral therapy is yet to be seen. In this study we investigated the effect of HIV infection and treatment on high-risk (hr) human papilloma virus (HPV) prevalence and distribution. Methods: Cervical cells from 515 (220 HIV positive and 295 HIV negative) women, recruited during community cervi
The relation between free-carrier absorption and intersubband transitions in semiconductor heterostructures is resolved by comparing a sequence of structures. Our numerical and analytical results show how free-carrier absorption evolves from the intersubband transitions in the limit of infinite number of wells with vanishing barrier width. It is explicitly shown that the integral of the absorption
Background: The n-3 polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, which are present in fish, are protective against myocardial infarction. However, fish also contains methylmercury, which influences the risk of myocardial infarction, possibly by generating oxidative stress. Methylmercury is metabolized by conjugation to glutathione, which facilitates elimination. Glut
Graves' disease (GD) is a complex autoimmune disorder characterized by hyperthyroidism and diffuse goitre. 25-50% of the patients with GD develop eye symptoms, Graves' ophthalmopathy (GO). The overall aim of this thesis was to explore the molecular etiology of GD and GO. By studying gene expression in Studies I, III, and IV, we demonstrated that adipocyte-related immediate early genes (IEGs) incl
Background: The social environment in which children grow up is closely associated with their health. The aim of this study was to investigate the relationship between maternal educational level, parental preventive behavior, parental risk behavior, social support, and use of medical care in small children in Malmo, Sweden. We also wanted to investigate whether potential differences in child medic
The Swedish Family-Cancer Database has been the major source of population-based prospective data on familial risks on most cancers, including prostate cancer. In the present review, I focus on three lines of family studies with novel results. The covered studies originate from the same database with publication dates spanning a period of somewhat over 3 years. Age-specific hazard ratios (HRs) of
We investigate the interaction between surface acoustic waves on a piezoelectric LiNbO3 substrate and charge carriers in InAs nanowire transistors. Interdigital transducers are used to excite electromechanical waves on the chip surface and their influence on the transport in the nanowire devices is studied at room temperature. Charge pumping is studied in different biasing conditions and in pulsed
