Giant Ultrabroadband Bulk Photovoltaic Effect Engendered by Two-Photon Absorption in α-In2Se3 for Chiral Terahertz Wave Generation
© 2024 Wiley‐VCH GmbH.
| Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - (2024) vom: 15. Dez., Seite e2416595 |
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| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
| Schlagworte: | Journal Article bulk photovoltaic effect chiral terahertz wave ferroelectric α‐In2Se3 two‐photon absorption |
| Zusammenfassung: | © 2024 Wiley‐VCH GmbH. Bulk photovoltaic effect (BPVE) can break the Shockley-Queisser limit by leveraging the inherent asymmetry of crystal lattice without a junction. However, this effect is mainly confined to UV-vis spectrum due to the wide-bandgap nature of traditional ferroelectric materials, thereby limiting the exploration of the infrared light-driven efficient BPVE. Herein, giant two-photon absorption (TPA) driven BPVE is uncovered from visible to infrared in ferroelectric α-In2Se3 utilizing wavelength-tunable terahertz (THz) emission spectroscopy. Remarkably, α-In2Se3 exhibits exceptional THz emission efficiency in the infrared region, surpassing renowned THz emitters like p-InAs and achieving an efficiency approximately eight times the magnitude of standard ZnTe. The power exponent-type pump fluence and quadruple polarization features reveal a unique TPA-driven BPVE, corroborated by a fourth-order nonlinear oscillator model. Notably, TPA-engendered BPVE efficiency approaches 68% of that observed in the single-photon absorption process. Moreover, the TPA responses display clear polarization anisotropy, with considerably relative phase and amplitude driven by synchronous in-plane and out-of-plane polarization, leading to chiral THz waves with high efficiency, tunable orientation, and controllable ellipticity. This work highlights the advantages of TPA-induced BPVE responses in narrow-bandgap ferroelectric semiconductors, enhancing spectral utilization efficiency, aiding high-performance devices based on BPVE, and guiding chiral THz wave design |
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| Beschreibung: | Date Revised 16.12.2024 published: Print-Electronic Citation Status Publisher |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.202416595 |