Photonics Research Group, Ghent University , 9000 Ghent, Belgium.
ACS Nano. 2015 Jan 27;9(1):778-88. doi: 10.1021/nn5062723. Epub 2015 Jan 13.
The cooling dynamics of hot charge carriers in colloidal lead chalcogenide nanocrystals is studied by hyperspectral transient absorption spectroscopy. We demonstrate a transient accumulation of charge carriers at a high energy critical point in the Brillouin zone. Using a theoretical study of the cooling rate in lead chalcogenides, we attribute this slowing down of charge carrier cooling to a phonon scattering bottleneck around this critical point. The relevance of this observation for the possible harvesting of the excess energy of hot carriers by schemes such as multiexciton generation is discussed.
通过高光谱瞬态吸收光谱研究了胶体铅硫属化物纳米晶体中热载流子的冷却动力学。我们在布里渊区的高能临界点证明了载流子的瞬态积累。通过对 lead chalcogenides 中冷却速率的理论研究，我们将载流子冷却速度的减慢归因于该临界点周围的声子散射瓶颈。讨论了这种观察对于通过多激子产生等方案来收集热载流子的过剩能量的可能意义。
