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...
Diese Arbeit befasst sich mit der Realisierung von AlGaN-basierten ultravioletten Leuchtdioden (LEDs) mit Emissionswellenlängen unterhalb von 250 nm sowie der Analyse ihrer strukturellen und elektrooptischen Eigenschaften. Ziel war es, eine LED mit einer mit möglichst maximaler spektraler Leistungsdichte bei 226 nm zu realisieren, welche es ermögli...
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 ...
Solarzellen auf Basis von Heterostrukturen aus hydrogeniertem amorphem (a-Si:H) und kristallinem Silizium (c-Si) sind Thema aktueller Forschungsvorhaben in der Photovoltaik. Das Zellkonzept verbindet das Potential hoher Wirkungsgrade von c-Si Wafern mit der vergleichsweise einfachen Prozessierung bei geringen Temperaturen von a-Si:H mittels der pla...
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 dieser Arbeit wird der Einfluss des Heterostrukturdesigns auf die externe Quanteneffizienz (EQE) von ultravioletten (UV) Leuchtdioden (LEDs) untersucht. Durch Simulationen der LED-Heterostruktur in Kombination mit Elektrolumineszenzmessungen an 320nm LEDs konnte eine gezielte Verbesserung der Heterostruktur und damit der internen Quanteneffizien...
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 ...
