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The Leibniz-Institut für Kristallzüchtung (IKZ) is a leading research institution in the area of science & technology as well as service & transfer of crystalline materials. Our goal is to enable solutions for urgent societal challenges (e.g. communication, artificial intelligence, climate protection, health etc.). by modern electronic & photonic technologies. The work covers the full spectrum from basic over applied research up to pre-industrial development and is performed in collaboration with national and international partners from university, academy and industry. The institute is part of the Forschungsverbund Berlin ( and a member of the Leibniz Association You can find more details on the institute webpage:

 We are currently seeking a highly motivated and talented individual to join our research team with a

PhD position (m/f/d)

for the topic:

 “Laser cooling of fluoride single crystals by anti-Stokes fluorescence”

Laser cooling of solids, or solid-state optical refrigeration, is a technology to cool solid materials down to cryogenic temperatures by laser excitation. The cooling is accomplished by anti-Stokes fluorescence which takes thermal energy away from a solid medium. This novel technology is the basis for ultra-stable laser coolers which are intrinsically free of vibrations. Therefore, laser coolers are attractive as a compact cooling system to be implemented in space satellites and also in ultra-sensitive detections such as gravitational wave detectors. This position offers an exciting opportunity to contribute to cutting-edge research at the intersection of materials science, optics, and laser physics.

As a PhD student, you will be involved in multidisciplinary research work focusing on crystal growth, chemical/physical characterization, and experiments using lasers. The primary objective of this study is to comprehensively understand the role of impurities, which currently pose a bottleneck for achieving temperatures below the boiling point of liquid nitrogen (77 K) in this technology. Our research group is widely recognized as one of the leading teams in this field, and this position will provide you with a unique platform to make significant contributions to the advancement of laser cooling techniques.

The key responsibilities of the PhD student will include:

  •         Growing high-quality fluoride single crystals doped with rare-earth ions
  •         Performing chemical and spectroscopic characterization of the crystals      
  •      Conducing laser cooling experiments using the grown fluoride crystals
  •         Collaborating with the research team to design and implement new experimental setups
  •         Analyzing and interpreting results, and contributing to scientific publications and conferences
  •         Keeping up-to-date with the latest research in the field of laser cooling and related areas.

The applicant must have:

  • A master’s degree (or equivalent) and strong knowledge in materials science, solid-state physics, optics, laser physics, or a closely related field
  • Experience in experimental research, preferably in crystal growth or optical characterizations
  • Excellent analytical, problem-solving, and communication skills
  • Ability to work independently as well as collaboratively in a team-oriented environment
  • Motivation and passion for scientific research.

For information about the project contact:                                                   
Dr. Hiroki Tanaka (IKZ),, Phone +49(0)30 6392 2821

The position is limited to three years, an extension for another year is possible. Payment is according to TVöD Bund (75 %) (Treaty for German public service) including the usual social benefits (30 vacation days in a 5-day week, flexible working hours). The IKZ is an equal opportunity employer and actively supports reconciliation of work and family life. There is equality for applicants of all genders. Qualified women are especially encouraged to apply. Among equally qualified applicants, preference will be given to disabled candidates.

Are you interested?
Then apply with a letter of motivation, curriculum vitae and all relevant certificates until the 15th of September 2023. To do so, please go to Job offers/jobs on our homepage and click on this advertisement and then on "Apply online".

We look forward to receiving your application!