Third-party funded projects

The key objective of this project is the development of integrated terahertz quantum-cascade lasers for high-resolution spectroscopy and future space applications at 3.5 THz and 4.7 THz. These two frequencies are very important for the detection of the OH radical and neutral atomic oxygen, respectively, in atmospheric research as well as in astronomy. The overarching goal is to integrate the QCL chip with optics for optical isolation, outcoupling, and beam shaping as well as an optical fiber.

PDI is currently building up an application laboratory for time-resolved cathodoluminescence spectroscopy, where the detectors will be optimized for ultraviolet wavelengths down to about 180 nm. The system will be capable of measuring classic semiconductor thin-films and heterostructures, 2D materials, as well as 3D nanostructures.

Microcavity exciton-polaritons (polaritons) are light-matter quasi-particles arising from the strong coupling of photons and quantum well excitons in a semiconductor microcavity. Polaritons are composite bosons with µm-sized thermal de-Broglie wavelengths (λdB) of several µm at temperatures of a few Kelvin. A gas of polaritons transitions to a collective single quantum state (an atomic Bose-Einstein-like condensate, BEC) when their λdB exceeds the average inter-particle distance. Own to the long λdB, a polariton BEC can be confined in µm-large intra-cavity traps produced by a lateral modulation of the cavity spacer thickness during the growth process (see figure).

The aim of the project “Nanoflex“ is to develop a novel piezoelectric energy harvester based on (Al,Sc)N nanowires as a lead-free and environmentally friendly alternative to conventional devices. This project, funded equally by German (DFG) and French (ANR) founding agencies, is a lively symbiosis of the scientific disciplines of materials science, physics, chemistry and device engineering.

A major challenge for a sustainable society is to ensure an economical consumption of energy. Electrical energy is a major part of today’s energy consumption and its fraction will continue to grow with increasing electromobility and digitalization of societies worldwide. This project aims to investigate novel semiconductor materials and their applications in power electronics for the development of more efficient high voltage transformers. Such devices are ubiquitously used in the electrical grid as well as electro mobility. By increasing their efficiency this project might constitute a pathway to energy saving and thus provide a significant contribution to a sustainable digital society.

Electronic components and sensors have become an indispensable part of everyday life: mobile phones, televisions and cars all need precise, lightweight, stable and inexpensive electronics. Two-dimensional, ultra-thin (atomically thin) layers are essential for these applications and the controlled manufacture of them is indispensable for the functionality and progress of our digital world. This basic research project looks at a novel manufacturing method for atomically thin, defect-free layer systems using focused ion beams supported by computer-based predictions of their electronic properties, as well as first attempts to implement them in electronic components.

This project aims to provide new experimental insights into the formation and impact of point defects in Ga2O3. We approach this challenge by cross-linking different experimental characterization techniques, such as micro-Raman spectroscopy and time-of-flight secondary ion mass spectroscopy (SIMS), on molecular beam epitaxy (MBE) grown Ga2O3 thin films deposited in well-defined regimes (i.e. metal- or oxygen-rich). We aim to provide concrete guidelines for the synthesis of Ga2O3 on how to avoid or engineer point defects as a means of controlling its functional properties.