热载流子动力学对电子、光电子、光伏和等离子器件的性能起着关键作用。热载流子的能量在纳米尺度和皮秒量级时间内损失，这一课题在理论计算和实验观测方面都具有挑战性。本项目中，我们拟采用密度泛函（微扰）理论结合多体微扰方法来研究类石墨烯二维材料中热载流子的弛豫性质（寿命），包括晶格弛豫对载流子散射机理及影响。通过计算电子-电子相互作用自能和电子-声子相互作用自能，我们能够给出热载流子的弛豫时间和平均自由程，并且可以把这些量直观的反映到相应的能带和k矢量上。通过对二维材料尺度的裁剪设计，可以将热载流子在小于自由程范围内的能量提取出来用以增加光伏器件的转换效率。该项目的研究结果将揭示二维材料中电-声子行为对热载流子动力学的影响，有助于推动类石墨烯二维材料电子器件的研发设计。

Hot carrier dynamics plays a key role in the performance of electronic, optoelectronic, photovoltaic and plasmonic devices. Hot carries lose energy over nanometer lengths and picosecond timescales and thus are challenging to study experimentally and theoretically. Here we are going to present density functional (perturbation) theory combining many-body perturbation theory to investigate hot carrier relaxation in graphene-like two-dimensional materials, including carrier relaxation mechanism and lifetime. After obtaining the electron-electron self-energies and electron-phonon self-energies, we can get the relaxation time and mean free path of hot carriers, and map the band and k dependence of these quantities. One can extract the energy within the mean free path in which the energy and momentum distributions of hot carriers are preserved, and thus enhance the efficiency of the optoelectronic devices. Our research will demonstrate the effect of electron-phonon interactions on the hot carrier dynamics in graphene-like two-dimensional materials and are able to push forward developing electronic devices based on there materials.