This award from the Major Research Instrumentation program supports scientists at Penn State University to develop new atomic resolution scanning probe optical spectroscopies by combining the spatial resolution of the scanning tunneling microscope (STM) with well-established, readily interpreted near ultraviolet, visible and infrared spectroscopies. A vital missing piece in the vast majority of scanning probe measurements is the ability to make unambiguous interpretations of images and chemical assignments of adsorbates. The researchers focus on adding spectroscopies that are already well established for ensemble-averaged measurements that can accomplish these assignments, specifically ultraviolet-visible (UV-Vis) and infrared (IR) spectroscopies. By coupling IR and optical spectroscopies with a local probe, the researchers will gain the ability to characterize and to identify individual nanostructures and even individual molecules and atoms based on their optical and electronic properties. This work will advance the state of the art in nanometer-scale science, measurement, and analysis. Optical spectroscopies provide well-understood methods to determine chemical identity and bonding changes and to determine electronic structure using IR and UV-Vis excitation, respectively. These capabilities will be combined to create a local optical spectrometer in the near UV, visible and IR, with wide applications in surface and interface science. Evanescent coupling will be utilized to deliver photons to the tunneling junction, using the STM tip as a detector. The surfaces studied will be well characterized, as they will be grown epitaxially on a variety of prisms. These experiments will complement the recently built dispersed photon emission STM built under the auspices of an instrument development grant from the NSF Divisions of Materials Research and Chemistry. These instruments will then be transitioned to the broader scientific community after development and optimization. Two talented graduate students and an undergraduate will participate in the fabrication of the new instruments.
This award from the Major Research Instrumentation program supports scientists at Penn State University to develop new atomic resolution scanning probe optical spectroscopies by combining the spatial resolution of the scanning tunneling microscope (STM) with well-established, readily interpreted near ultraviolet, visible and infrared spectroscopies. A vital missing piece in the vast majority of scanning probe measurements is the ability to make unambiguous interpretations of images and chemical assignments of adsorbates. The researchers focus on adding spectroscopies that are already well established for ensemble-averaged measurements that can accomplish these assignments, specifically ultraviolet-visible (UV-Vis) and infrared (IR) spectroscopies. By coupling IR and optical spectroscopies with a local probe, the researchers will gain the ability to characterize and to identify individual nanostructures and even individual molecules and atoms based on their optical and electronic properties. This work will advance the state of the art in nanometer-scale science, measurement, and analysis. These instruments will then be transitioned to the broader scientific community after development and optimization. Two talented graduate students and an undergraduate will participate in the fabrication of the new instruments.
