Giant bulk photovoltaic effect driven by the wall-to-wall charge shift in WS2 nanotubes

Photo-induced quantum phenomena observed in two-dimensional transition metal dichalcogenides (TMDs) have attracted substantial scientific interest, which is to be combined with novel opportunities in future for advanced optoelectronic devices [1, 2]. Among the family of TMDs, the one-dimensional nanotube is particularly attractive because it produces a spontaneous photocurrent which is absent in its higher-dimensional counterparts [3]. We present that TMD nanotubes provide a giant shift current near the infrared region, which amounts to four times the value previously reported in the higher frequency range [4]. The key geometrical advantage is ascribable to the wall-to-wall charge shift, and we consider a Janus-type heteroatomic configuration as an example that maximizes such advantage. To go beyond the perturbative treatment of the electronic states near the ground states, we carried out the real-time integration of the photoinduced current using time-dependent density functional theory, which can take the full nonlinear effect of strong fields into account. Our findings can lead to new avenues for low-dimensional optoelectronic devices and provide a solid basis for a complete quantum mechanical understanding of the unique light–matter interaction rooted in the geometric characteristics of the reduced dimension.

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[3] Zhang, Y. J. et al. Enhanced intrinsic photovoltaic effect in tungsten disulfide nanotubes. Nature 570, 349–353 (2019)

[4] Kim, B., Park, N., Kim, J., Giant bulk photovoltaic effect driven by the wall-to-wall charge shift in WS2 nanotubes. Nat. Commun. 13, 3237 (2022)