Tailoring Broadband Nonlinear Optical Characteristics and Ultrafast Photocarrier Dynamics of Bi 2 O 2 S Nanosheets by Defect Engineering.

Autor: Dong J; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Zhang L; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Lau K; Institute of Light+X Science and Technology, Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, Zhejiang, 315211, China., Shu Y; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Wang S; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Fu Z; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Wu Z; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Liu X; School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China., Sa B; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Pei J; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Zheng J; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Zhan H; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China., Wang Q; College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, China.; College of Materials Science and Engineering, Fujian University of Technology, Fuzhou, 350118, China.; School of Resources & Chemical Engineering, Sanming University, Sanming, 365004, China.
Jazyk: angličtina
Zdroj: Small (Weinheim an der Bergstrasse, Germany) [Small] 2024 Jun; Vol. 20 (24), pp. e2309595. Date of Electronic Publication: 2023 Dec 28.
DOI: 10.1002/smll.202309595
Abstrakt: Low-dimensional bismuth oxychalcogenides have shown promising potential in optoelectronics due to their high stability, photoresponse, and carrier mobility. However, the relevant studies on deep understanding for Bi 2 O 2 S is quite limited. Here, comprehensive experimental and computational investigations are conducted in the regulated band structure, nonlinear optical (NLO) characteristics, and carrier dynamics of Bi 2 O 2 S nanosheets via defect engineering, taking O vacancy (OV) and substitutional Se doping as examples. As the OV continuously increased to ≈35%, the optical bandgaps progressively narrow from ≈1.21 to ≈0.81 eV and NLO wavelengths are extended to near-infrared regions with enhanced saturable absorption. Simultaneously, the relaxation processes are effectively accelerated from tens of picoseconds to several picoseconds, as the generated defect energy levels can serve as both additional absorption cross-sections and fast relaxation channels supported by theoretical calculations. Furthermore, substitutional Se doping in Bi 2 O 2 S nanosheets also modulate their optical properties with the similar trends. As a proof-of-concept, passively mode-locked pulsed lasers in the ≈1.0 µm based on the defect-rich samples (≈35% OV and ≈50% Se-doping) exhibit excellent performance. This work deepens the insight of defect functions on optical properties of Bi 2 O 2 S nanosheets and provides new avenues for designing advanced photonic devices based on low-dimensional bismuth oxychalcogenides.
(© 2023 Wiley‐VCH GmbH.)
Databáze: MEDLINE
Externí odkaz: