Colour centres in device quality synthetic diamond
NPF is active in the field of nanoscale optical spectroscopic imaging using ultrasensitive techniques based on manipulation of single photons or electronic spins. The group works with high purity single crystal CVD diamond plates and devices (prepared in collaboration with the WBGM group) and study Nitrogen Vacancy (NV) along with other colour centres that can be considered as artificial molecules in solids. NV centres offer the possibility to initialize, coherently manipulate and optically read-out spin states. The developed techniques enables interaction with the quantum-size objects and their use in nanoscale super-resolution imaging. Nano scale devices are used for detection of minute magnetic and electric fields, electrical charges and temperature on the atomic scale, i.e. quantum metrology. This ongoing research also has high relevance and prospects for quantum photonics in biological systems and quantum information processing.
Nanoscale sensors and imaging
Another focus of the group are luminescent biocompatible nanoparticles specifically, fluorescent nanodiamonds (FND), that have important prospects for nanoscale imaging in biology and medicine. FND particles, 5 – 50 nm size are being developed in several EU-funded projects. By functionalizing the FND with biomolecules, intracellular sensors for detection of biochemical processes with high spatial resolution are prepared. Single photon confocal microscopy and optical detected magnetic resonance (ODMR) are used as imaging tools for FNDs. Another example is the development of novel imaging techniques for neurosciences applied for contactless detection of action potential of interacting of neurons in neural networks. Neurons are cultured and interfaced to nanoscale diamond devices in collaboration with BIOMED group and international partners.
Ultrasensitive spectroscopic techniques
Ultrasensitive spectroscopic techniques such as photothermal deflection spectroscopy (PDS) and photocurrent spectroscopy are very powerful tools to optimize the external quantum efficiency (EQE) in nanostructured devices including solar cells such as CGS, OBHJ, peroskvite-based etc. These techniques allow characterization of density of states related to defects in the bandgap of such materials and the study of charge transfer mechanism.
Involvement in international research
The group has been strongly involved in the EU-funded international research (FP7 EU projects DINAMO, MOLESOL, DIAMANT, DIADEMS, NAMASEN, MERIDIAN) and organisation of important conferences, workshops and symposia in the field. About 10 Material Research Society Meetings symposia have been organized by the group, including the symposium Quantum photonics, information technology and sensing, to be part of the MRS Spring Meeting 2015 in San Francisco.