Near-Field Optical Spectroscopy Centre at Sheffield, NOSC

The function of many new materials that drive innovation and even the function of the living micro-systems such as bacteria is defined by their nanoscale properties such as the local chemical composition, ability to transfer and dissipate energy and electrical charge, local crystal structure and nanometre-sized defects, ability to scatter and trap light, or to induce chemical reactions through catalysis and many more. Understanding how we can prolong the life-time of devices, for example a battery cathode or a solar cell, can also be gained from understanding of how the material in the device changes on the nanoscale during its operation. It has long been a drive to develop technical means that allow to 'see' with nanometer resolution, an impossible task if conventional 'far-field' optical microscopy is used, because of the diffraction limit. The optical diffraction limit can be overcome if high energy electrons are used instead of light, but such electron microscopy may be damaging for the studied materials and nano-structures and quite often requires special sample preparation.

Truly non-invasive techniques relying on weak optical probes are therefore highly desirable, and have now become available in state-of-the-art experimental instruments. In this project, we will establish a research facility based on such an instrument, which provides a unique suite of novel optical techniques capable of 10 nm spatial resolution, 50 to 1000 times below the optical diffraction limit. The techniques are based on the light focusing with a very sharp tip, used in atomic force microscopy (AFM). Such techniques will operate in conjunction with the powerful nanoscale investigation method provided by AFM. The facility will provide this experimental platform for the world-leading research at the University of Sheffield and the UK scientific community as a whole in topics including artificial photosynthesis, antimicrobial resistance, inorganic and organic semiconductors, quantum and bioinspired nano-photonics, two-dimensional materials, solar cells, photocatalysis and nano-materials for solid state batteries among many others. Common to all these fields is the challenge of mapping structural, chemical and functional properties with nanoscale resolution; a challenge that prevents further breakthroughs in understanding and innovation in the technology areas that are vital to the UK's interests, and which we will address within the proposed nano-spectroscopy facility.