Measuring the Electronic Bandgap of Carbon Nanotube Networks in Non-Ideal Diodes.

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 diodes.

Andreev Reflection and Klein Tunneling in High-Temperature Superconductor-Graphene Junctions.

Scattering processes in quantum materials emerge as resonances in electronic transport, including confined modes, Andreev states, and Yu-Shiba-Rusinov states. However, in most instances, these resonances are driven by a single scattering mechanism. Here, we show the appearance of resonances due to the combination of two simultaneous scattering mechanisms, one from superconductivity and the other from graphene p-n junctions.

All-Carbon Nanotube Solar Cell Devices Mimic Photosynthesis.

Both solar cells and photosynthetic systems employ a two-step process of light absorption and energy conversion. In photosynthesis, they are performed by distinct proteins. However, conventional solar cells use the same semiconductor for optical absorption and electron-hole separation, leading to inefficiencies.

Direct Measurement of the Electron Beam Spatial Intensity Profile via Carbon Nanotube Tomography.

Electron microscopes are ubiquitous across the scientific landscape and have been improved to achieve ever smaller beam spots, a key parameter that determines the instrument's resolution. However, the traditional techniques to characterize the electron beam have limited effectiveness for today's instruments. Consequently, there is an ongoing need to develop detection technologies that can potentially measure the smallest electron beam, which is valuable for the continual advancement of microscope performance.