Room-temperature wavelike exciton transport in a van der Waals superatomic semiconductor
Room-temperature wavelike exciton transport in a van der Waals superatomic semiconductor
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DOI：
10.1126/science.adf2698
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发表时间：
2023-06
期刊：
影响因子：
56.9
通讯作者：
Jakhangirkhodja A. Tulyagankhodjaev;Petra Shih;Jessica Yu;Jake C. Russell;Daniel G. Chica;Michelle E. Reynoso;Haowen Su;Athena C. Stenor;Xavier Roy;Timothy C. Berkelbach;Milan Delor
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作者：
Jakhangirkhodja A. Tulyagankhodjaev;Petra Shih;Jessica Yu;Jake C. Russell;Daniel G. Chica;Michelle E. Reynoso;Haowen Su;Athena C. Stenor;Xavier Roy;Timothy C. Berkelbach;Milan Delor
半导体中能量和信息的传输受到电子载流子和晶格声子之间散射的限制，导致扩散和有损传输，从而限制了所有半导体技术。利用货车范德华（vdW）超原子半导体Re 6Se 8 Cl 2，我们证明了声激子-极化子的形成，声激子-极化子是一种电子准粒子.我们直接成像极化子运输Re 6Se 8 Cl 2在室温下，揭示准弹道，波状传播持续纳秒和几微米。屏蔽极化子传输导致电子能量传播长度的数量级大于其他vdW半导体，甚至超过硅超过纳秒。我们建议，违反直觉，准平坦的电子带和强激子-声学声子耦合一起负责Re 6Se 8 Cl 2的输运性质，建立一个弹道室温半导体的路径。材料内部的能量载体会遇到来自杂质和晶格振动等来源的阻力。扩展平均自由程，即载波经历的碰撞之间的距离，对于应用是重要的。Tulyagankhodjaev等人在货车范德华半导体Re 6Se 8 Cl 2中实现了这一目标。研究人员利用光来产生激子（空穴和电子对），然后对它们的传输进行成像。粒子在室温下以准弹道的方式传播了几微米。这种异常强大的运输可以归因于激子的绑定到声学晶格变形。-Jelena Stajic超快频闪散射显微镜用于跟踪货车德瓦尔斯半导体Re 6Se 8 Cl 2中的激子输运。
The transport of energy and information in semiconductors is limited by scattering between electronic carriers and lattice phonons, resulting in diffusive and lossy transport that curtails all semiconductor technologies. Using Re6Se8Cl2, a van der Waals (vdW) superatomic semiconductor, we demonstrate the formation of acoustic exciton-polarons, an electronic quasiparticle shielded from phonon scattering. We directly imaged polaron transport in Re6Se8Cl2 at room temperature, revealing quasi-ballistic, wavelike propagation sustained for a nanosecond and several micrometers. Shielded polaron transport leads to electronic energy propagation lengths orders of magnitude greater than in other vdW semiconductors, exceeding even silicon over a nanosecond. We propose that, counterintuitively, quasi-flat electronic bands and strong exciton–acoustic phonon coupling are together responsible for the transport properties of Re6Se8Cl2, establishing a path to ballistic room-temperature semiconductors. Description Editor’s summary Energy carriers inside materials encounter resistance from sources such as impurities and lattice vibrations. Extending the mean free path, the distance between the collisions that the carriers experience, is important for applications. Tulyagankhodjaev et al. achieved this goal in the van der Waals semiconductor Re6Se8Cl2. The researchers used light to create excitons (pairs of holes and electrons) and then imaged their transport. The particles propagated quasiballistically over several micrometers at room temperature. This unusually robust transport could be attributed to the binding of excitons to an acoustic lattice deformation. —Jelena Stajic Ultrafast stroboscopic scattering microscopy is used to track exciton transport in the van der Waals semiconductor Re6Se8Cl2.