At the Department of Electrical Engineering and Information Technology, TU Darmstadt, Germany, the Terahertz Devices and Systems Laboratory offers a

PhD position

on the topic „ErAs:In(Al)GaAs-based Photoconductive Terahertz Devices” yet limited to a duration of 36 months with a targeted starting date of January 1st 2021.

The research topic are photoconductive materials based on ErAs:In(Al)GaAs for generation and detection of THz radiation (100 GHz-10 THz). These so-called photoconductors are driven by a (telecom-) laser signal (either a short pulse with a pulse duration <100 fs, or two continuous-wave lasers with a difference frequency of the desired THz frequency. Absorption of the laser signal leads to a modulation of the conductivity of the material at THz frequencies. If the device is operated as THz source, a further DC bias is applied, leading to a THz-modulated current that is subsequently radiated by an attached antenna. If operated as detector, a THz signal is directed onto an antenna which converts the THz radiation to a THz bias. This is used to bias the photoconductive material that is, at the same time, illuminated with a laser signal as described previously. This way, the received THz bias is mixed with the laser signal, yielding a DC component that is proportional to the THz field strength. The focus will lie on detector structures. However, some applications will also require development of photoconductive sources, in particular for pulsed operation.

The work will include, amongst others, the design of the devices and their antenna structures, processing of the devices in a clean room, integration of finished devices with electronics and optical components, characterization of the developed structures, carrying out applications, as well as paper writing and conference contributions. Assistance in projects funded by the deutsche Forschungsgemeinschaft will be requested. Research is performed within an international team with friendly atmosphere.

The applicant shall fulfill the following requirements:

  • An excellent university degree (MSc./Diploma) in one of the following subjects is a prerequisite: Physics, Electrical Engineering or Materials Science
  • The applicant shall have knowledge/experience in at least two of the following topics:
    • Semiconductor physics
    • Experience with lasers and fiber optics
    • Terahertz
    • Clean room experience
  • Experience in Matlab and LabView are helpful. German language abilities are highly desirable.

We expect excellent, independent research and support explicitly publications in peer-reviewed scientific journals and at renowned conferences, as well as collaboration with other research groups.

We offer the opportunity to complete a PhD (further work may be required) as well as participation in national and international conferences. Further information is available under:

Opportunity for further qualification (doctoral dissertation) is given. The fulfillment of the duties likewise enables the scientific qualifications of the candidate.

The Technische Universität Darmstadt intends to increase the number of female employees and encourages female candidates to apply. In case of equal qualifications applicants with a degree of disability of at least 50 or equal will be given preference. Wages and salaries are according to the collective agreements on salary scales, which apply to the Technische Universität Darmstadt (TV-TU Darmstadt). Part-time employment is generally possible.

Your application should include: Your curriculum vitae, MSc/Diploma certificates and grades, a letter of motivation stating your interest in the position and topic, an optional reference letter from the Master thesis supervisor will be helpful.

Please send your electronic application to Prof. Sascha Preu ( with the subject “Photoconductors2020 - Code-No. 449”.

Code No. 449

Published on

September 07, 2020

Application deadline

October 15, 2020