Aletheia, W., Jiang, M., Cao, M., Huang, S., Lourembam, J., Ma, X., Duan, R., & Liu, Z. (2026). Nonlinear optical processes in 2D Cairo pentagonal palladium phosphide sulfide. Nano Research, 19(6), 94908387. https://doi.org/10.26599/nr.2026.94908387
Abstract:
Anisotropic nonlinear optical two-dimensional (2D)
materials hold great potential for advancing photonics and
optoelectronics applications due to their coexistence of strong
nonlinear optical response and high nonlinear anisotropy ratio,
such as crystal orientation identification, bio-microscopy, optical
switching. This work focused on the unique layer-dependent
symmetry breaking and strong second harmonic generation
(SHG) anisotropy based on palladium phosphide sulfide (PdPS), a
pentagonal 2D semiconductor with Cairo tiling. PdPS exhibits
even-layer inversion symmetry breaking and highly tunable SHG
anisotropy, contrast to odd-layer inversion symmetry. Notably, the
SHG anisotropy ratio reaches up to 32.7 for six layers (< 5 nm) PdPS. This ratio is the highest in such thin 2D materials to
the best of our knowledge. Furthermore, its optical properties can be tuned easily through layer number and microdevice
configuration. As layer number of PdPS decreases from six layers to two layers, the anisotropic ratio drops drastically from
32.7 to 0.89. In addition, the overall SHG signal can be increased by 10 times when integrated with a photonic crystal
device. These findings suggest that PdPS holds great promise for use in polarization-sensitive and layer-engineered
nonlinear photonic applications like photodetectors, polarized lasers, polarized light emitting diodes and reflective polarizer.
License type:
Attribution 4.0 International (CC BY 4.0)
Funding Info:
This research / project is supported by the A*STAR - Singapore RIE2025 Manufacturing, Trade, and Connectivity (MTC) Young Individual Research Grants (YIRG)
Grant Reference no. : M23M7c0129, H23-MRG0293
This research / project is supported by the A*STAR - Singapore RIE2025 Manufacturing, Trade, and Connectivity (MTC) Individual Research Grants (IRG)
Grant Reference no. : M23M6c0104, H23-MRG0268
This research is supported by core funding from: Quantum Innovation Centre (Q. InC) core funding
Grant Reference no. : NIL
This research / project is supported by the National Research Foundation (NRF) - Competitive Research Programme (CRP)
Grant Reference no. : NRF-CRP22-2019-0007
This research / project is supported by the National Research Foundation (NRF) - Competitive Research Programme (CRP)
Grant Reference no. : NRF-CRP31-0001
This research / project is supported by the National Research Foundation (NRF) - Competitive Research Programme (CRP)
Grant Reference no. : NRF-CRP264-2021-0004
This research / project is supported by the A*STAR - A*STAR SERC Manufacturing, Trade and Connectivity (MTC) Programmatic Fund
Grant Reference no. : M23M2b0056
This research / project is supported by the Singapore Ministry of Education (MOE) - Academic Research Fund Tier 3
Grant Reference no. : MOEMOET32023-0003
This research / project is supported by the Singapore Ministry of Education (MOE) - Academic Research Fund Tier 2
Grant Reference no. : MOE-T2EP50223-0008
This research / project is supported by the Singapore Ministry of Education - Academic Research Fund Tier 1
Grant Reference no. : 023785-00001 (RT7/23)
This research / project is supported by the A*STAR - Manufacturing, Trade and Connectivity (MTC) Program Young Individual Research Grants (YIRG)
Grant Reference no. : M24N8c0097