Shin Taeho, Teitelbaum Samuel W, Wolfson Johanna, Kandyla Maria, Nelson Keith A
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
J Chem Phys. 2015 Nov 21;143(19):194705. doi: 10.1063/1.4935366.
Thermal modeling and numerical simulations have been performed to describe the ultrafast thermal response of band gap materials upon optical excitation. A model was established by extending the conventional two-temperature model that is adequate for metals, but not for semiconductors. It considers the time- and space-dependent density of electrons photoexcited to the conduction band and accordingly allows a more accurate description of the transient thermal equilibration between the hot electrons and lattice. Ultrafast thermal behaviors of bismuth, as a model system, were demonstrated using the extended two-temperature model with a view to elucidating the thermal effects of excitation laser pulse fluence, electron diffusivity, electron-hole recombination kinetics, and electron-phonon interactions, focusing on high-density excitation.
已经进行了热建模和数值模拟，以描述带隙材料在光激发下的超快热响应。通过扩展适用于金属但不适用于半导体的传统双温度模型建立了一个模型。它考虑了光激发到导带的电子的时间和空间相关密度，从而能够更准确地描述热电子与晶格之间的瞬态热平衡。作为一个模型系统，铋的超快热行为使用扩展的双温度模型进行了演示，旨在阐明激发激光脉冲能量密度、电子扩散率、电子-空穴复合动力学和电子-声子相互作用的热效应，重点是高密度激发。
