Multidimensional Coherent Spectroscopy Revealing the Hidden Properties of Nanomaterials
Abstract
Semiconducting nanomaterials have emerged, nearly 40 years ago, as a promising platform for novel technologies. They offer a rich environment for the study of fundamental physics and allow for an unprecedented level of control over the electronic and optical properties in condensed matter. One of the inherent difficulties in studying these nanostructures is due an intrinsic property that considerably hinges the observation of their electronic structure and many body phenomena: inhomogeneous spectral broadening. Caused by thickness fluctuation in films, size distribution in nanoparticles, and other structural variations, this spectral broadening generally overwhelms any subtle features, detectable otherwise with optical spectroscopy. In this project, we use multidimensional coherent spectroscopy, a technique capable of separating the inhomogeneous contribution from other features in a spectrum, to reveal details of the electronic fine structure in these nanomaterials. Our method, which combines a sequence of three excitation ultrafast laser pulses and a gate pulse for heterodyne detection, mounted on an ultra-stable platform, allows for the detection of spectral features with sub-meV resolution and 10´s of femtoseconds temporal resolution. This high resolution allows us to investigate how quantum confinement and changes in shape, size and composition affect fundamental aspects of the nanomaterials, including splits of the exciton ground state, dipole moment orientations, electron-phonon coupling, intrinsic linewidth, among others.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110370XX0
Entities
People
- Lazaro A Padilha
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Campinas