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Training in: Epitaxial growth of novel semiconductor nanostructures, optical and structural characterization of materials, device processing in clean room and optoelectronic characterization.

Efficient light sources and detectors for the mid-infrared wavelength range between 2 and 7 µm are key for optical gas sensing systems and enable a broad range of applications spanning from medical diagnostics, environmental monitoring to safety applications. Interband cascade lasers and detectors enable lowest threshold current densities and large detectivities, respectively, and are hence good candidates to be utilized in this emerging field.

The research will focus on the design, fabrication (epitaxial growth and nano-structuring) and characterization of interband cascade nanostructures and superlattices based on the antimonide-related 6.1A material system. The goal of the project is to develop optimal light sources and detectors based on the interband cascade (IC) scheme to be employed in tunable laser based gas sensing applications in the mid-infrared wavelength region (2-7 µm). We seek to investigate in detail the electronic transport properties of InAs/GaSb semi-metallic quantum wells in combination with InAs/AlSb superlattices, which are the building blocks of interband cascade sources and detectors.

The experimental work will be comprised of the epitaxial growth of samples containing InAs/GaSb interfaces and superlattice, the characterization of the barrier and quantum well layer morphology by use of scanning and transmission electron microscopy and atomic force microscopy, as well as their optical properties by several spectroscopic setups. Electro-optical characterization tools will be used to characterize and optimize the relevant figure of merits, such as quantum efficiency, detectivity, output power, wall-plug efficiency etc.

Environment

Institution: The University of Würzburg, Germany, was founded already in 1402, and has currently ten faculties with around 425 professors and 29,000 students. A total of 14 Nobel Laureates have – at least temporarily – researched and taught at the Julius-Maximilians-Universität Würzburg.
Institute/Laboratory: During the last three decades, the chair for Technical Physics (‘Technische Physik’, TEP) at the University of Würzburg has developed into one of the leading research facilities in the field of nanostructures and optoelectronics. The chair conducts both fundamental as well as application-oriented research mainly based on III-V semiconductors in the GaAs, InP, GaSb and GaP material systems. The chair operates a 550 m² clean room with a complete semiconductor technology line, including growth with MBE-systems, lateral patterning by optical, electron and ion-beam lithography, and several etching and deposition systems.
Location/City: The city of Würzburg is located in the north of Bavaria and well connected via train to e.g. Frankfurt airport and Munich.

Requirements

We seek an excellent, open-minded and team-spirited PhD candidate with:
Graduation: a Physics or Engineering degree.
Post-graduation: Previous experience in a research environment involving solid state and semiconductor physics, epitaxial growth or nanostructure fabrication will be positively considered.
Other: The successful candidate should have good knowledge and interest in experimental work.

How to Apply

Candidates can apply to a maximum of four different ESR positions in the network using the links below. Applications must include the following documents:
  1. An internal application form listing your academic and job records (.docx template available here).
  2. A free format CV (pdf format max 2 Mb)
  3. Official documentation such as degree and grades certificates will be required at a later stage.
The deadline for application is 31st January 2021.
Attempts to apply to more than four positions using different registration profiles will invalidate your candidature.