PhD Student (f/m/d)

Tätigkeitsprofil:

The underlying material system is the (Al,Ga)N alloy, which currently represents the most promising semiconductor platform for optoelectronics operating in the UV-C spectral range. Despite significant technological progress, UV-C LED emitters still exhibit limited efficiency and reliability. The aim of the project is hence to identify the underlying mechanisms responsible for optical degradation in such devices. In particular, the project focuses on the evolution of defects under electrical and thermal stress, which limits both the electrical-to-optical conversion efficiency, as well the operational lifetime of these devices. The project involves optical and electrical in operando characterization techniques using custom-designed setups, mainly involving

• Acquisition of detailed electrical data and optical emission information.
• Cathodoluminescence measurements.

Since degradation experiments typically extend over one week or longer, all measurements are performed in a fully automated manner. This includes the development of Python-based control and automation routines, as well as the analysis of large experimental datasets.

These characterization techniques may be complemented by X-ray-based in operando investigations that reveal structural information related to stress. Experimental work will be carried out predominantly in the IKZ laboratories. For advanced X-ray investigations, beamtime applications are planned at major synchrotron radiation facilities, including KIT (Karlsruhe), ESRF (Grenoble), and DESY (Hamburg). Regular scientific exchange, joint meetings, and collaborative experiments are integral parts of the project and essential for its successful completion.

Anforderungsprofil:

• MSc degree in physics, materials science, or a related discipline
• Knowledge of semiconductor physics, particularly optoelectronics
• Hands-on experience in optical spectroscopy
• Good programming skills, ideally in Python
• Ability to collaborate and coordinate work within a team of scientists, technicians, and students
• Strong command of English; basic knowledge of German is beneficial

Prior experience in the following areas is considered an asset:

• Design and/or operation of optical setups
• Scanning electron microscopy / cathodoluminescence spectroscopy