Bulk photovoltaic effect in transition metal dichalcogenide nanotube

The bulk photovoltaic effect (BPVE) converts light energy to electric energy without need of built-in potential. Hence, its conversion efficiency will not be restricted by the Shockley-Queisser limit. However, the BPVE efficiency of existing bulk materials are quite small. Here, we introduced a nanotube made of the representative two-dimensional material WS₂ in the research field of BPVE. We not only observed BPVE for the first time in nano-materials, but also revealed a high conversion efficiency in WS₂ nanotube. Furthermore, our systematic study unveiled the importance of the polar structure on the enhancement of BPVE. Our results are anticipated to put forward the BPVE study based on polar nano-materials. (author)