Sunlight is widely seen as one of the most abundant forms of renewable energy, with photovoltaic cells based on pn junctions being the most commonly used platform attempting to harness it. Unlike in conventional photovoltaic cells, the bulk photovoltaic effect (BPVE) allows for the generation of photocurrent and photovoltage in a single material without the need to engineer a pn junction and create a built-in electric field, thus offering a solution that can potentially exceed the Shockley–Queisser efficiency limit. However, it requires a material with no inversion symmetry and is therefore absent in centrosymmetric materials. Here, we demonstrate that breaking the inversion symmetry by structural disorder can induce BPVE in ultrathin PtSe₂, a centrosymmetric semiconducting van der Waals material. Homogenous illumination of defective PtSe₂ by linearly and circularly polarized light results in a photoresponse termed as linear photogalvanic effect (LPGE) and circular photogalvanic effect (CPGE), which is mostly absent in the pristine crystal. First-principles calculations reveal that LPGE originates from Se vacancies that act as asymmetric scattering centers for the photo-generated electron-hole pairs. Our work emphasizes the importance of defects to induce photovoltaic functionality in centrosymmetric materials and shows how the range of materials suitable for light sensing and energy-harvesting applications can be extended.

阳光被广泛视为最丰富的可再生能源形式之一，基于 pn 结的光伏电池是尝试利用阳光的最常用平台。与传统光伏电池不同，体光伏效应 (BPVE) 允许在单一材料中产生光电流和光电压，而无需设计 pn 结并创建内置电场，从而提供了一种可能超过肖克利-奎瑟效率极限。然而，它需要一种不具有反演对称性的材料，因此在中心对称材料中不存在。在这里，我们证明通过结构无序打破反演对称性可以在超薄 PtSe ₂（一种中心对称半导体范德华材料）中诱导 BPVE。通过线性和圆偏振光均匀照射有缺陷的 PtSe ₂会产生称为线性光电效应 (LPGE) 和圆形光电效应 (CPGE) 的光响应，这在原始晶体中几乎不存在。第一性原理计算表明，LPGE 源自 Se 空位，Se 空位充当光生电子空穴对的不对称散射中心。我们的工作强调了缺陷在中心对称材料中诱导光伏功能的重要性，并展示了如何扩展适合光传感和能量收集应用的材料范围。