Ultrafast optical spectroscopy was used to characterize the temporal response and energies of hot electrons (above the bandgap) in optically excited colloidal quantum wells (CQWs) as a function of monolayer (ML) thickness.
Significance and Impact
Hot electrons enable the extraction of greater energy and increased energy conversion efficiency of optoelectronic devices. The challenge is that hot electrons are typically short lived and have varied energies in different materials and structures. This work establishes the evolution of energy vs time after photoexcitation of hot electrons in novel nanoscale CQWs of varying thicknesses, and also shows how to produce them in a controlled manner.
About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.
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