Nonradiative Relaxation of Photoexcited Black Phosphorus Is Reduced by Stacking with MoS2: A Time Domain ab Initio Study
Nonradiative Relaxation of Photoexcited Black Phosphorus Is Reduced by Stacking with MoS2: A Time Domain ab Initio Study
复制标题
通过与 MoS2 堆叠减少光激发黑磷的非辐射弛豫：时域从头开始研究
DOI：
10.1021/acs.jpclett.6b00757
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发表时间：
2016
影响因子：
5.7
通讯作者：
Fang Weihai
中科院分区：
文献类型：
--
作者：
Long Run;Guo Meng;Liu Lihong;Fang Weihai
黑磷（BP）具有可调的直接带隙和高载流子迁移率，在电子和光电子领域具有广泛的应用前景。对于真正的光电器件利用，非辐射电子-空穴复合应该是缓慢的，因为它是电荷和能量损失的主要途径。利用时域密度泛函理论结合非绝热（NA）分子动力学，我们发现在几十皮秒内双层BP中发生了非辐射电子-空穴复合，与实验数据吻合较好。当单层BP与单层MoS2叠加时，与双层BP相比，由于带隙增加和电子-声子NA耦合减少，复合减少。与双层BP相比，BP- mos2van der Waals异质结中电子-声子能量损失缓慢，这表明BP与其他二维材料的合理叠加是设计新型高效光伏材料的一条有吸引力的途径。
Black phosphorus (BP) is an appealing material for applications in electronics and optoelectronics because of its tunable direct band gap and high charge carrier mobility. For real optoelectronic device utilization, nonradiative electron–hole recombination should be slow because it constitutes a major pathway for charge and energy losses. Using time-domain density functional theory combined with nonadiabatic (NA) molecular dynamics, we show that nonradiative electron–hole recombination occurs within several tens of picoseconds in bilayer BP, agreeing well with experimental data. When a single layer of BP is stacked with monolayer MoS2, the recombination is reduced because of the increased band gap and reduced electron–phonon NA coupling compared to bilayer BP. The slow electron–phonon energy losses in BP-MoS2van der Waals heterojunction relative to bilayer BP indicate that rationally stacking BP with other two-dimensional materials is an attractive route for designing novel and efficient photovoltaic materials.