AlGaN-based ultraviolet-C (UVC) light emitting diodes (LEDs) can be applied to a wide range of applications. However, the efficiency of UVC-LEDs is still relatively modest, which provides the focus of this thesis: The development of efficient UVC-LEDs with emission wavelengths near 265 nm. This thesis presents a systematic study of the influence of...
Annealing-induced solid phase crystallization of In₂O₃:H leads to a significantly improved electron mobility, which is confirmed by Hall measurements. Indium hydroxide dehydroxylation occurs in In₂O₃:H during annealing, which is well responsible for the structural transformation and a high electron mobility with a decreased carrier concentration in...
In this work the realization of AlGaN-based ultraviolet light emitting diodes (LEDs) with emission wavelengths below 250 nm as well as the analysis of their structural and electrooptical properties is presented. The aim of this work was to achieve an LED with a maximum spectral power density at 226 nm, which allows the detection of nitrogen oxide w...
This thesis focuses on the electronic transport properties and low temperature quantum effects of mesoscopic GaAs/InAs core/shell nanowires. This radial nanowire heterostructure combines an electrically insulating GaAs core with a highly conductive InAs shell. Owing to this alignment, the movement of the conduction electrons is limited to a ring-li...
In this thesis, the growth and structural properties of III-V semiconductor nanowires and nanowire heterostructures are studied. These nanowires represent structures suitable for both fundamental physics and applications in electronic devices such as (tunnel) field effect transistors. The III-V nanowires are grown with molecular beam epitaxy, high ...
The complexity of today´s microelectronic circuitry is not only driven by complementary metal oxide semiconductor (CMOS) scaling, but also by integration of high performance modules for various applications (e.g. wireless and broadband communication systems). These mixed signal circuitries are build up by combining digital CMOS technology with anal...
Analogous to semiconductor heterostructures, interfaces between polar and non-polar perovskite oxides can exhibit novel electronic properties. Complex oxide heterostructures thus have potential for electronic applications not only due to the inherent material properties of oxides but also due to the properties of their interfaces. Metallic conducti...
In this paper, we give an overview of quantum cascade detector technology for the near- and mid-infrared wavelength range. Thanks to their photovoltaic operating principle, the most advanced quantum cascade detectors offer great opportunities in terms of high detection speed, reliable room temperature operation, and excellent Johnson noise limited ...
The influence of the growth method on the surface potential and thus on the sheet carrier concentration of GaN capped Al(x)Ga(1-x)N/GaN heterostructures was evaluated. Nominally undoped low pressure metal-organic vapor-phase (MOVPE) and plasma-assisted molecular beam epitaxial (PA-MBE) grown structures with an Al-content between 12% and 30% yield c...
An overview of quantum cascade detector technology for the near- and mid-infrared wavelength range will be given. Thanks to photovoltaic instead of photoconductive operation, quantum cascade detectors offer great opportunities in terms of detection speed, room temperature operation, and detectivity. Besides some crucial issues dealing with fabricat...
