We love diamonds and the little nitrogen vacancy centers within them.

One of our current research directions is to develop high-performance integrated photonic, quantum photonic and optoelectronic devices based on on-chip monolithically integrated quantum nanowire (NW) heterostructures. Specific examples include NW-based lasers and non-classical single photon emitters based on NW-QD (-quantum dot) devices for next-generation information technology, quantum communi­cat­ion and sensing. Hereby, an important task is to explore the optical and photonic responses of the respective systems using advanced confocal luminescence spectroscopy along with simulations, where e.g. the effects of the quantized electronic structure, light-matter interactions, or the coupling of light to on-chip photonic circuits are probed. The following key publications illustrate our current work on integrated photonic NW-based devices and their properties.

From tunable dielectrics integrated into nanoscale electronic devices to multifunctional coatings that promote efficient solar-to-chemical energy conversion, we make extensive use of atomic layer deposition (ALD) to precisely engineer interfaces, design novel heterostructures, and introduce defined functionalities at surfaces. Within this research, we develop novel ALD processes and materials, guided by in situ spectroscopic ellipsometry and mass spectrometry that offer real-time insights into nucleation dynamics, growth kinetics, defect formation, and film properties. Moving beyond traditional approaches, we explore advanced ALD strategies by, for example, integrating plasma-surface interactions to tune interfacial chemical and electronic properties, introducing external stimuli to achieve area-selective growth, and tailoring reaction conditions to shape nanoscale morphologies. By advancing ALD-based methods for precise interface and material control, our work contributes to the development of next-generation electronic, energy, and catalytic systems in which nanoscale structure-property relationships are critical.

While 2D semiconductors offer unique electronic and optical properties, realization of their full potential requires scalable growth and controlled integration into functional assemblies. In our research, we aim to create defined 2D/3D heterostructures using chemical vapor deposition (CVD) of transition metal dichalcogenides (TMDs) onto engineered substrates. These heterostructures include thin film junctions and laterally patterned substrates that enable precise spatial control of the 2D material and its electronic environment. In addition, we take advantage of low-temperature atomic layer deposition (ALD) processes to precisely tune interaction lengths and strengths between TMDs and their surroundings. A major emphasis of this work on 2D semiconductor assemblies is devoted to elucidating interfacial mechanisms that govern charge transfer pathways, energetic alignment, and structural and chemical interactions, providing a basis for future applications spanning from advanced optoelectronics to photocatalytic energy conversion.