Ghosh Atish, Ball Biswajit, Pal Sougata, Sarkar Pranab
Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India.
Department of Chemistry, University of Gour Banga, Malda 732103, India.
J Phys Chem Lett. 2022 Sep 1;13(34):7898-7905. doi: 10.1021/acs.jpclett.2c02196. Epub 2022 Aug 18.
In search of an efficient solar energy harvester, we herein performed a time domain density functional study coupled with nonadiabatic molecular dynamics (NAMD) simulation to gain atomistic insight into the charge carrier dynamics of a graphitic carbon nitride (g-CN)-tungsten telluride (WTe) van der Waals heterostructure. Our NAMD study predicted ultrafast electron (589 fs) and hole-transfer (807 fs) dynamics in g-CN/WTe heterostructure and a delayed electron-hole recombination process (2.404 ns) as compared to that of the individual g-CN (3 ps) and WTe (0.55 ps) monolayer. The ultrafast charge transfer is due to strong electron-phonon coupling during the charge-transfer process while comparatively weak electron-phonon coupling, sufficient band gap, comparatively lower nonadiabatic coupling (NAC), and fast decoherence time slow down the electron-hole recombination process. The NAMD results of exciton relaxation dynamics are valuable for insightful understanding of charge carrier dynamics and in designing photovoltaic devices based on organic-inorganic 2D van der Waals heterostructures.
为了寻找一种高效的太阳能收集器，我们在此进行了时域密度泛函研究，并结合非绝热分子动力学（NAMD）模拟，以从原子层面深入了解石墨相氮化碳（g-CN）-碲化钨（WTe）范德华异质结构中的电荷载流子动力学。我们的NAMD研究预测，与单个g-CN（3 ps）和WTe（0.55 ps）单层相比，g-CN/WTe异质结构中存在超快电子（589 fs）和空穴转移（807 fs）动力学以及延迟的电子-空穴复合过程（2.404 ns）。超快电荷转移是由于电荷转移过程中强烈的电子-声子耦合，而相对较弱的电子-声子耦合、足够的带隙、相对较低的非绝热耦合（NAC）以及快速的退相干时间减缓了电子-空穴复合过程。激子弛豫动力学的NAMD结果对于深入理解电荷载流子动力学以及设计基于有机-无机二维范德华异质结构的光电器件具有重要价值。
