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Training in: Modeling of quantum transport using the nonequilibrium Green’s function (NEGF) method in interband cascade devices, type-II superlattices and memory devices.

Interband cascade lasers (ICL) are semiconductor heterostructures consisting of a periodic repetition of atomically thin quantum wells and barriers. ICLs emit in the mid-infrared spectrum and are used for environmental gas sensing. The exact understanding of the microscopic details of the quantum transport properties in the active region is complicated and not completely understood but essential in order to further optimize these devices. For modeling the quantum transport properties of quantum cascade lasers (QCL), the nonequilibrium Green’s function (NEGF) method is state of the art. However, it has never been applied to interband cascade lasers so far.

The modeling of the electronic states in these devices requires a multiband k.p model and depends very sensitively on the thickness and material composition of the layers. The objective is to develop a multiband model of nonequilibrium Green’s functions calculating quantum transport and optical properties of III-Sb devices, applicable to III-Sb ICLs, memory arrays and type-II superlattices.

The candidate will extend our existing NEGF software for quantum cascade lasers by adding the valence bands within an 8-band k.p model so that electron and hole transport can be treated on an equal footing. This will include an accurate description of conduction band to valence band tunnelling which is the most challenging part of ICL devices. The developed software will also be applied to model type-II superlattices and memory devices. With these new features and the knowledge generated, the improved nextnano software will greatly facilitate the design and optimization of these III-Sb quantum devices and accelerate their commercialization.

Environment

Institution: nextnano GmbH develops and sells software for the simulation of electronic and optoelectronic semiconductor nanodevices for both academic research and industrial research and development. Examples include nanotransistors, LEDs, laser diodes, photodetectors, quantum dots, nanowires, quantum cascade lasers and solar cells. The focus is on the simulation of the quantum mechanical properties of such devices. The nextnano software is used by more than 250 customers in more than 35 countries.
Location/City: nextnano GmbH is located in Munich, Germany. One employee is based in Grenoble, France.

Requirements

We seek an excellent, open-minded, entrepreneurial and team-spirited PhD candidate with:
Graduation: a Master in Physics or Electrical Engineering with focus on theoretical physics (solid state physics, semiconductor physics, quantum mechanics).
Previous experience in a research environment involving semiconductor physics will be positively considered.
Other: The successful candidate should have excellent knowledge of solid-state theory, semiconductor physics and programming skills. Excellent communication skills and ability to work in an international environment will be strongly appreciated.

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.