Accelerating discovery of infrared nonlinear optical materials with large shift current via high-throughput screening

Abstract

Discovering nonlinear optical (NLO) materials with strong shift current response, particularly in the infrared (IR) regime, is essential for next-generation optoelectronics yet remains highly challenging in both experiments and theory, which still largely relies on case by case studies. Here, we employ a high-throughput screening strategy, applying a multi-step filter to the Materials Project database (>154,000 materials), which yielded 2,519 candidate materials for detailed first-principle evaluation. From these calculations, we identify 32 NLO materials with strong shift current response ($σ$ > 100 $μA/V^2$). Our work reveals that layered structures with $C_{3v}$ symmetry and heavy $p$-block elements (e.g. Te, Sb) exhibit apparent superiority in enhancing shift current. More importantly, 9 of these compounds show shift current response peaks in the IR region, with the strongest reaching 616 $μA/V^2$, holding significant application potential in fields such as IR photodetection, sensing, and energy harvesting. Beyond identifying promising candidates, this work establishes a comprehensive and high-quality first-principles dataset for NLO response, providing a solid foundation for future AI-driven screening and accelerated discovery of high-performance NLO materials, as demonstrated by a prototype machine-learning application.

Figures (7)

• Figure 1: Schematic illustration of traditional photovoltaic effect (PVE) and bulk photovoltaic effect (BPVE). (a) Traditional PVE devices, such as p-n junctions, utilize the built-in electric field near the junction interface to separate photo-excited carriers. (b) BPVE is an intrinsic photovoltaic phenomenon occurring in non-centrosymmetric materials, relying on spontaneous polarization induced by structural asymmetry to separate photo-excited charge carriers without requiring heterojunctions or interfaces. (c) The shift current mechanism in real space on light-induced interband excitation. In non-centrosymmetric crystals, the displacement of the electron cloud during the excitation of electrons from the valence band to the conduction band generates a net current known as shift current.
• Figure 2: Database screening and high-throughput calculations. (a) The workflow of high-throughput screening process. Initially, filters based on symmetry, band gap, number of atoms, magnetic properties, and elemental composition are applied. Subsequently, DFT calculations are conducted to obtain the Hamiltonian and band structure. Following this, the DFT Hamiltonians are utilized to compute the shift current response at the PBE level. Ultimately, 32 materials with high shift current response are identified as potential candidates. Importantly, further calculations at the HSE level are performed for these target candidates to refine the results. (b) The distribution of 56 elements in the periodic table for 2,519 noncentrosymmetric materials, where the color intensity represents the frequency of occurrence in all screened materials, and the numbers below the chemical symbols show the count of occurrence of that element. Gray represents elements that did not appear in this study.
• Figure 3: The calculated maximum shift current response tensor and its corresponding photon energy at the (a) PBE and (b) HSE levels, with the colorbar revealing the band gap of 32 compounds with shift current conductivity of over 100 $\mu A/V^2$ and the gray circles indicate the remaining compounds. The background color reveals the response wavelength of the calculated materials, which falls within the infrared (IR), visible (VIS), or ultraviolet (UV) spectrum. The 9 compounds in Tab. \ref{['tab:sc_IR']} that exhibit IR shift current response are labeled.
• Figure 4: The calculated the maximum peak of the shift current at the PBE and HSE levels for 32 compounds with higher nonlinear optical response. The pie chart in the inset displays the relative proportions of 8 noncentrosymmetric point groups among these 32 compounds, while the periodic table on the right illustrates their elemental distribution and frequencies.
• Figure 5: The Band structures for the infrared candidates. Red solid lines and blue dashed lines correspond to PBE and HSE results, respectively.