Tracking Ultrafast Charge Dynamics in Energy Materials with Atomic Specificity
Abstract
I propose to design and construct a table-top ultrafast X-ray spectrometer that can track thecharge dynamics in complex energy materials with unprecedented atomic/chemical specificities ina label-free manner. Currently, there is little experimental approach that can reveal theatomic/chemical sites around the charges as charge separation, recombination and migrating occurin solid state materials. Thus, there is lack of knowledge of the relationships between localatomic/chemical site of charges and the charge dynamics. The proposed spectroscopy will fill thisvoid and lead to develop new energy materials with atomic precision.Using this new spectrometer, my team will investigate the charge dynamics of hybridperovskite solar cell materials – a material with up to 20% power conversion efficiency and greatpotential to be used in warfare and civil settings. Its photophysics is yet understood, which is alarge obstacle to further improve its efficiency and stability. In particularly, the physical origins ofits low electron-hole recombination rate and low density charge traps – two key properties behindits superior efficiency, remain unclear. We aim to reveal the origin of these key properties usingthe atomic/chemical specific time resolved x-ray spectroscopy. This proposed research will deepenour understanding of the fundamental photophysics of perovskite, which is critical for improvingits efficiency and longer lifespan.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 02, 2017
- Source ID
- FA95501710094
Entities
People
- Wei Xiong
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California, San Diego