Terahertz Charge Carrier Mobility in 1D and 2D Semiconductor Nanoparticles

We investigate the charge carrier mobility in 1D and 2D semiconductor nanoparticle domains with a focus on the interpretation of THz mobility measurements. We provide a microscopic understanding of the frequency-dependent charge carrier transport in these structures of finite lateral size. Yet unexplored oscillations in the frequency- dependent complex conductivity and a strong size dependence of the mobility are observed. The quantum nature of the charge carrier states results in oscillations in the frequency-dependent mobility for subresonant THz probing, seen in experiments. The effect is based on the lack of an energy continuum for the charge motion. In 2D systems the mobility is further governed by transitions in the two orthogonal xand y-directions and depends nontrivially on the THz polarization, as well as the quantum well lateral aspect ratio, defining the energetic detuning of the lowest THz-photon transitions in both directions. We analyze the frequency, length, and effective mass dependencies.

Automated summary

This study focuses on the charge carrier mobility in 1D and 2D semiconductor nanoparticle domains, providing insights into the frequency-dependent charge carrier transport and observing unexplored oscillations in the frequency-dependent complex conductivity. The quantum nature of charge carrier states leads to oscillations in the frequency-dependent mobility, particularly for subresonant THz probing. In 2D systems, the mobility is further affected by transitions in two orthogonal directions, THz polarization, and the quantum well lateral aspect ratio, defining the energetic detuning of the lowest THz-photon transitions.