This paper demonstrates that breaking the inversion symmetry by structural disorder can induce the bulk photovoltaic effect (BPVE) in ultrathin PtSe₂, a centrosymmetric semiconducting van der Waals material. Homogenous illumination of defective PtSe₂ with linearly and circularly polarized light results in a photoresponse (linear and circular photogalvanic effects, LPGE and CPGE) absent in pristine crystals. First-principles calculations reveal that LPGE originates from Se vacancies acting as asymmetric scattering centers. This work highlights the potential of defect engineering to induce photovoltaic functionality in centrosymmetric materials, expanding the range of materials for light sensing and energy harvesting.

Cheol-Yeon Cheon, Zhe Sun, Jiang Cao, Juan Francisco Gonzalez Marin, Mukesh Tripathi, Kenji Watanabe, Takashi Taniguchi, Mathieu Luisier, Andras Kis