Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS) , Ludwig-Maximilians-Universität München , Geschwister-Scholl-Platz 1 , 80539 München , Germany.
The Barcelona Institute of Science and Technology , ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology , 08860 Castelldefels , Spain.
Nano Lett. 2018 Jul 11;18(7):4136-4140. doi: 10.1021/acs.nanolett.8b00871. Epub 2018 Jun 25.
We demonstrate that localized excitons in luminescent carbon nanotubes can be utilized to study electrostatic fluctuations in the nanotube environment with sensitivity down to the elementary charge. By monitoring the temporal evolution of the cryogenic photoluminescence from individual carbon nanotubes grown on silicon oxide and hexagonal boron nitride, we characterize the dynamics of charge trap defects for both dielectric supports. We find a one order of magnitude reduction in the photoluminescence spectral wandering for nanotubes on extended atomically flat terraces of hexagonal boron nitride. For nanotubes on hexagonal boron nitride with pronounced spectral fluctuations, our analysis suggests proximity to terrace ridges where charge fluctuators agglomerate to exhibit areal densities exceeding those of silicon oxide. Our results establish carbon nanotubes as sensitive probes of environmental charge fluctuations and highlight their potential for applications in electrometric nanodevices with all-optical readout.
我们证明，发光碳纳米管中的局域激子可用于研究纳米管环境中的静电涨落，其灵敏度可低至基本电荷。通过监测在氧化硅和六方氮化硼上生长的单个碳纳米管的低温光致发光的时间演化，我们对两种介电支撑材料的电荷俘获缺陷的动力学进行了表征。我们发现，在原子级平坦的六方氮化硼上生长的纳米管的光致发光光谱漂移减少了一个数量级。对于在具有明显光谱波动的六方氮化硼上的纳米管，我们的分析表明，这些纳米管接近阶地脊，在那里电荷涨落体聚集在一起，表现出的面密度超过氧化硅。我们的结果确立了碳纳米管作为环境电荷涨落的敏感探针，并强调了它们在具有全光学读出的静电纳米器件中的应用潜力。
