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Abstract：
The measurement of the electronic bandgap and exciton binding energy in quasi-one-dimensional materials such as carbon nanotubes is challenging due to many-body effects and strong electron-electron interactions. Unlike bulk semiconductors, where the electronic bandgap is well known, the optical resonance in low-dimensional semiconductors is dominated by excitons, making their electronic bandgap more difficult to measure. In this work, we measure the electronic bandgap of networks of polymer-wrapped semiconducting single-walled carbon nanotubes (s-SWCNTs) using non-ideal p-n diodes. We show that our s-SWCNT networks have a short minority carrier lifetime due to the presence of interface trap states, making the diodes non-ideal. We use the generation and recombination leakage currents from these non-ideal diodes to measure the electronic bandgap and excitonic levels of different polymer-wrapped s-SWCNTs with varying diameters: arc discharge (~1.55 nm), (7,5) (0.83 nm), and (6,5) (0.76 nm). Our values are consistent with theoretical predictions, providing insight into the fundamental properties of networks of s-SWCNTs. The techniques outlined here demonstrate a robust strategy that can be applied to measuring the electronic bandgaps and exciton binding energies of a broad variety of nanoscale and quantum-confined semiconductors, including the most modern nanoscale transistors that rely on nanowire geometries.
摘要：
由于多体效应和强电子-电子相互作用，准一维材料如碳纳米管中的电子带隙和激子结合能的测量具有挑战性。与块状半导体不同，电子带隙是众所周知的，低维半导体中的光学共振由激子主导，使其电子带隙更难以测量。在这项工作中,我们使用非理想p-n二极管测量聚合物包裹的半导体单壁碳纳米管（s-SWCNT）网络的电子带隙。我们表明，由于界面陷阱态的存在，我们的s-SWCNT网络具有较短的少数载流子寿命，使二极管不理想。我们使用这些非理想二极管的生成和重组泄漏电流来测量不同直径的不同聚合物包裹的s-SWCNT的电子带隙和激子水平：电弧放电（〜1.55nm），(7.5)(0.83nm),和(6,5)(0.76nm)。我们的价值观与理论预测一致，深入了解s-SWCNT网络的基本特性。这里概述的技术展示了一种强大的策略，可用于测量各种纳米级和量子限制半导体的电子带隙和激子结合能，包括依赖于纳米线几何形状的最现代的纳米级晶体管。
