BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:In situ spectroscopy and nanoscale imaging of  electrochemical ene
 rgy conversion and storage systems
DTSTART:20240926T141500
DTEND:20240926T150000
DTSTAMP:20260921T221101Z
UID:668210b76a2920d6935eff5a9e1b47743eb9dc26c8c9003cdc785f33
CATEGORIES:Conferences - Seminars
DESCRIPTION:Justin Sambur Associate Professor Department of Chemistry Scho
 ol of Advanced Materials Discovery (SAMD) Colorado State University\, Fort
  Collins\, CO 80523  \n            The first part of my talk w
 ill focus on solar energy conversion. The fundamental problem that limits 
 the solar energy conversion efficiency of conventional semiconductors such
  as Si is that all absorbed photon energy above the band gap is lost as he
 at. The critical question that our research addresses is: Can we avoid ene
 rgy losses in semiconductors? Ultrathin 2D semiconductors such as monolaye
 r (ML) MoS2 and WSe2 have unique physical and photophysical properties tha
 t could make high-efficiency\, hot-carrier energy conversion possible. Our
  research team has employed photocurrent spectroscopy\, steady-state absor
 ption spectroscopy\, and in situ femtosecond transient absorption spectros
 copy as a function of applied potential to characterize underlying steps i
 n a ML MoS2 photoelectrochemical cell. The rich data set informs us on th
 e timescales for hot-carrier generation/cooling and exciton formation/reco
 mbination\, as well as the magnitudes of changes in exciton energy levels\
 , exciton binding energies\, and the electronic band gap. These findings o
 pen the possibility of tuning the hot-carrier extraction rate relative to 
 the cooling rate to ultimately utilize hot-carriers for solar energy conve
 rsion applications. The second part of my talk will focus on elucidating c
 harge storage mechanisms in nanoscale materials\, which underlies the perf
 ormance of electrochemical technologies such as batteries and smart window
 s. I will discuss our high-throughput electro-optical imaging method that 
 measures the battery-like and capacitive-like (i.e.\, pseudocapacitive) ch
 arge storage contributions in single metal oxide nanoparticles.  I will p
 resent our single particle-level measurements that show (1) individual par
 ticles exhibit different charge storage mechanisms at the same applied po
 tential and (2) particle size-dependent pseudocapacitive charge storage pr
 operties.\n\nJustin Sambur is the Monfort Associate Professor of Chemistry
  at Colorado State University. Justin earned his B.S. degree in 2006 from 
 the State University of New York (SUNY)-Binghamton. His undergraduate hono
 rs thesis work under the direction of Dr. David Doetschmann focused on the
  degradation mechanisms of chemical warfare agents within zeolite pores. J
 ustin traveled west to graduate school and earned his PhD under the direct
 ion of Dr. Bruce A. Parkinson at Colorado State University (CSU). Justin s
 tudied the photoelectrochemical energy conversion properties of semiconduc
 tor nanocrystals and light absorbing polymers on single crystal electrode 
 surfaces. In 2011\, Justin traveled back to NY to join Prof. Peng Chen’s
  lab at Cornell University. Justin’s NSF ACC-F Postdoctoral Fellow work 
 integrated single molecule imaging methods in the area of photoelectrochem
 istry. Justin returned to CSU in 2016 as an Assistant Professor of Chemist
 ry and the School of Advanced Materials Discovery (SAMD). His research has
  been recognized with the Royce Murray Young Investigator Award\, Air Forc
 e Young Investigator Award\, NSF CAREER Award\, and DOE Early Career Award
 . Justin was also named a Sloan Research Fellow and a Scialog Fellow in Ad
 vanced Energy Storage.
LOCATION:CH G1 495 https://plan.epfl.ch/?room==CH%20G1%20495 https://epfl.
 zoom.us/j/84209090880
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR