Uncovering the Effects of Nanoscale Materials Heterogeneity through Multimodal and Correlative Microscopies

The past decade has witnessed remarkable advances applying the transformative insight of ultrafast spectroscopies to the nanoscale. By coupling femtosecond laser pulses into far-field microscopes, the spatial and energetic evolution of electrons can be correlated to specific micro- and nanoscale structural features, providing important insight into how anisotropic crystal structures, strongly interacting excited states, and structural and electronic defects influence the behavior of active (opto)electronic devices. In this talk, I’ll discuss work done by our group developing and applying ultrafast microscopies that provide new contrast agents and means to correlate structure with function in a variety of nanoscale and bulk materials. I’ll show our efforts developing excited state stimulated Raman microscopy, which provides a means to directly probe how electrons couple with vibrational degrees of freedom on the femtosecond time scale and on sub-200 nm length scales. In addition, I’ll describe recent efforts that have directly correlated electron motion to local crystal structure, thereby directly probing how electron motion is governed by the local defect density and lattice strain in bulk materials.