Optical Materials最新文献_第3页

Reflectivity improvement of lightweight active cooled metal mirrors manufactured by additive manufacturing 增材制造技术改进轻量化主动冷却金属反射镜的反射率

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-29 DOI: 10.1016/j.optmat.2025.117570

Ignas Bitinaitis , Karolis Stravinskas , Sergejus Borodinas , Genrik Mordas , Alexandr Belosludtsev

{"title":"Reflectivity improvement of lightweight active cooled metal mirrors manufactured by additive manufacturing","authors":"Ignas Bitinaitis , Karolis Stravinskas , Sergejus Borodinas , Genrik Mordas , Alexandr Belosludtsev","doi":"10.1016/j.optmat.2025.117570","DOIUrl":"10.1016/j.optmat.2025.117570","url":null,"abstract":"<div><div>In recent years, additive manufacturing (AM) has appeared as a revolutionary approach in designing and fabricating active-cooled mirrors (ACMs). In particular, selective laser melting (SLM) allows more design freedom (with high resolution) while reducing weight and material costs compared to conventional manufacturing methods. In the current research, SLM using a Ytterbium fiber laser (200 W, 1030 nm) and a high-speed scanner for precise active cooled mirror base manufacturing was used. Nevertheless, without a proper surface finish, the metal surface has relatively low reflectance. This limits the use of element for laser and space-based applications. In the present research, we show how HR silver-aluminum (Ag–Al) mixed coating deposited using magnetron sputtering may help. The final element reflectance was increased up to >95 % in the vis-IR range and the arithmetic average roughness was less than 3–5 nm. Optical performance and surface quality were evaluated in each manufacturing step. Fabricated coatings' properties are compared with those used in earlier space missions to assess their main parameters. Additive manufacturing approach successfully enabled the integration of complex internal cooling channels that cannot be achieved through conventional machining methods, providing a foundation for enhanced thermal management in high-power optical applications.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117570"},"PeriodicalIF":4.2,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improvement of electronic structure, optical properties, and crystalline quality of FAPbI3 perovskite thin films by poly(ionic liquid) additives based on polymerized TFSI ion 基于聚合TFSI离子的聚离子液体添加剂改善FAPbI3钙钛矿薄膜的电子结构、光学性能和晶体质量

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-29 DOI: 10.1016/j.optmat.2025.117569

Vladimir Rajić , Barbara Ramadani , Nemanja Latas , Miloš Milović , Rajat Rai , Daniele Mantione , Milutin Ivanović

{"title":"Improvement of electronic structure, optical properties, and crystalline quality of FAPbI3 perovskite thin films by poly(ionic liquid) additives based on polymerized TFSI ion","authors":"Vladimir Rajić , Barbara Ramadani , Nemanja Latas , Miloš Milović , Rajat Rai , Daniele Mantione , Milutin Ivanović","doi":"10.1016/j.optmat.2025.117569","DOIUrl":"10.1016/j.optmat.2025.117569","url":null,"abstract":"<div><div>Over the past decade, organic-inorganic halogen perovskite solar cells (PSCs) have made significant stride toward achieving record efficiencies. However, their long-term stability under ambient conditions, largely hindered by the perovskite material itself, remains a major obstacle to large-scale production. Herein, we present two novel poly(ionic liquid)s (PILs) as promising additives to improve the quality of formammidinium lead iodide (FAPbI<sub>3</sub>) perovskite thin films. The synthesized PILs, Poly(lithium bis(trifluoromethanesulfonyl)imide) and Poly(imidazolium bis(trifluoromethanesulfonyl)imide) abbreviated as [PMTFSI] Li and [PMTFSI] [DCMim], respectively, are based on polymerized TFSI anions which have shown great potential for healing the defects in the perovskite structure. The presence of multiple functional groups in PILs structure, such as sulfonyl, carbonyl, nitrile, trifluoromethyl, N+ in imidazolium, renders the interaction with the host perovskite materials, efficiently passivating defects throughout the perovskite film. Obtained results are further compared with the results acquired for the counterpart salt lithium bis(trifluoromethanesulfonyl)imide shortly LiTFSI or [TFSI] Li. This study highlights the potential of PILs based on polymerized TFSI for the preparation of FAPbI<sub>3</sub> thin films under ambient conditions with enhanced crystalline quality which is expected to improve both the stability and efficiency of PSCs.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117569"},"PeriodicalIF":4.2,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative analysis of light transmission in thin-film materials across multiple laser wavelengths using partial least squares regression 利用偏最小二乘回归对薄膜材料在多个激光波长上的光传输进行比较分析

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-27 DOI: 10.1016/j.optmat.2025.117566

Ahmed Abdelhady A. Khalil , Omnia Hamdy

{"title":"Comparative analysis of light transmission in thin-film materials across multiple laser wavelengths using partial least squares regression","authors":"Ahmed Abdelhady A. Khalil , Omnia Hamdy","doi":"10.1016/j.optmat.2025.117566","DOIUrl":"10.1016/j.optmat.2025.117566","url":null,"abstract":"<div><div>Thin-film composites have significance in optoelectronics, photonics, and sensing technologies because of their unique optical properties. This work examines the light transmission behavior of six thin-film materials: Cu, ZnO, Ni, MoS<sub>2</sub>, MoS<sub>2</sub>–SiC, and ITO/MoS<sub>2</sub> under continuous wave (CW) laser irradiation at wavelengths of 405, 532, 670, 830, and 980 nm. The experimental results were analyzed using Partial Least Squares Regression (PLSR) to derive material-specific optical fingerprints and multivariate spectral responses. The PLSR model achieved a root mean squared error (RMSE) of 3305.17 and identified more than 95 % of the variance with five latent components. MoS<sub>2</sub> had the highest transmission at 405 nm, followed by Ni at 532 and 980 nm, and ZnO at 830 nm. Cu continuously had the lowest transmission. These findings provide important insights into the wavelength-dependent behavior of thin films and can help guide material selection and optimization for application in transparent electrodes, optical coatings, photodetectors, and laser-based systems.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117566"},"PeriodicalIF":4.2,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Light/heating/humidity induced reversible transformation between CsPb2Br5 and CsPbBr3 for switchable photoluminescence and heterostructure diodes 光/热/湿诱导CsPb2Br5和CsPbBr3在可切换光致发光和异质结构二极管之间的可逆转化

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-27 DOI: 10.1016/j.optmat.2025.117555

Liming Zhang , Zhuang Zhao , Siyu Chen , Wei Chen , Xuying Zhong , Yuehua Peng , Yanling Yin , Jun Liu , Wei Dou , Dongsheng Tang , Weichang Zhou

{"title":"Light/heating/humidity induced reversible transformation between CsPb2Br5 and CsPbBr3 for switchable photoluminescence and heterostructure diodes","authors":"Liming Zhang , Zhuang Zhao , Siyu Chen , Wei Chen , Xuying Zhong , Yuehua Peng , Yanling Yin , Jun Liu , Wei Dou , Dongsheng Tang , Weichang Zhou","doi":"10.1016/j.optmat.2025.117555","DOIUrl":"10.1016/j.optmat.2025.117555","url":null,"abstract":"<div><div>CsPb<sub>2</sub>Br<sub>5</sub> has attracted a tremendous attention recently owing to its high stability and unusual optical properties. However, the transformation between CsPb<sub>2</sub>Br<sub>5</sub> and CsPbBr<sub>3</sub> has yet been fully understood and the origin of the bright green emission in CsPb<sub>2</sub>Br<sub>5</sub> is still under debate<strong>.</strong> In this work, we elucidate the mechanism of the abnormal green emission in CsPb<sub>2</sub>Br<sub>5</sub> and reveal the light/heating/humidity induced reversible transformation between CsPb<sub>2</sub>Br<sub>5</sub> and CsPbBr<sub>3</sub>. The detailed structure characterization indicates the successful synthesis of pure phase CsPb<sub>2</sub>Br<sub>5</sub>, which exhibits a non-luminous feature. Remarkably, after the treatment of ultraviolet laser irradiation or annealing, the pure phase CsPb<sub>2</sub>Br<sub>5</sub> can be transformed partially or completely into CsPbBr<sub>3</sub>, yielding an unexpected bright green emission. In addition, the transformed CsPbBr<sub>3</sub> can be converted back to CsPb<sub>2</sub>Br<sub>5</sub> under the humidity environment, demonstrating the reversible transformation and photoluminescence switch. Interestingly, CsPbBr<sub>3</sub> derived from transformed CsPb<sub>2</sub>Br<sub>5</sub> exhibits superior emission properties such as higher photoluminescence stability, compared with the one-spot directly synthesized CsPbBr<sub>3</sub>. Moreover, the light induced transformation facilitates the fabrication of CsPb<sub>2</sub>Br<sub>5</sub>/CsPbBr<sub>3</sub> nano-heterostructure diodes with a high rectification ratio. These results provide an important insight into the photophysics and transformation mechanism of all-inorganic Cs-Pb-Br perovskites for photonics/electronics device applications.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117555"},"PeriodicalIF":4.2,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low-cost and high-performance ITO/ZnO/ITO multilayer structure for silicon heterojunction solar cells 用于硅异质结太阳能电池的低成本、高性能ITO/ZnO/ITO多层结构

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-26 DOI: 10.1016/j.optmat.2025.117565

Emre Kartal , Ayşe Seyhan , Furkan Güçlüer

{"title":"Low-cost and high-performance ITO/ZnO/ITO multilayer structure for silicon heterojunction solar cells","authors":"Emre Kartal , Ayşe Seyhan , Furkan Güçlüer","doi":"10.1016/j.optmat.2025.117565","DOIUrl":"10.1016/j.optmat.2025.117565","url":null,"abstract":"<div><div>Transparent conducting oxides (TCOs) are critical for effective light transmission and charge collection in silicon heterojunction (SHJ) solar cells. While indium tin oxide (ITO) remains the standard choice, its high cost and material scarcity have motivated the search for alternative or complementary materials. Zinc oxide (ZnO), known for its wide bandgap and chemical stability, has emerged as a promising candidate. In this study, an ITO/ZnO/ITO multilayer structure is proposed as a cost-effective and efficient alternative to conventional single-layer TCO configurations in SHJ solar cells. Using OPAL-2 optical simulations and experimental fabrication via magnetron sputtering, the trilayer design demonstrated enhanced light absorption, reduced surface reflectance, and improved charge transport properties. Importantly, the structure achieved a power conversion efficiency (PCE) of 18.5 %, representing a 6 % and 11 % relative improvement over ITO-only and ZnO-only configurations, respectively, while reducing ITO consumption by approximately 14 %. These results highlight the potential of ITO/ZnO/ITO multilayers to optimize device performance and lower material costs, offering a practical pathway toward more sustainable SHJ solar cell technologies.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117565"},"PeriodicalIF":4.2,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tailoring the morphological, optical, luminescence, and gas sensing properties of SILAR-grown ZnO thin films: an impact of adsorption time silar生长ZnO薄膜的形态、光学、发光和气敏特性：吸附时间的影响

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-26 DOI: 10.1016/j.optmat.2025.117567

Mohd Shkir , Mohd Taukeer Khan , R. Marnadu , Aslam Khan , Farhat S. Khan , Thamraa Alshahrani

{"title":"Tailoring the morphological, optical, luminescence, and gas sensing properties of SILAR-grown ZnO thin films: an impact of adsorption time","authors":"Mohd Shkir , Mohd Taukeer Khan , R. Marnadu , Aslam Khan , Farhat S. Khan , Thamraa Alshahrani","doi":"10.1016/j.optmat.2025.117567","DOIUrl":"10.1016/j.optmat.2025.117567","url":null,"abstract":"<div><div>Controlling thin film growth parameters is critical for tailoring the functional properties of metal oxide semiconductors. This study investigate the influence of adsorption time during the successive ionic layer adsorption and reaction (SILAR) process on the structural, optical, photophysical, and ammonia (NH<sub>3</sub>) gas sensing properties of zinc oxide (ZnO) thin films. Precursor immersion time was systematically varied (5–20 s) to engineer microstructure and enhance device performance. Structural analysis via X-ray diffraction (XRD) and Raman spectroscopy showed that increasing adsorption time promotes crystallinity, enlarges crystallite size (from 16.56 to 27.88 nm), and reduces microstrain and defect density. Field-emission scanning electron microscopy (FESEM) revealed a morphological evolution from granular clusters to vertically aligned nanorods, increasing active surface area. Optical absorption spectra demonstrated a redshift in the band edge and a narrowing of the optical bandgap from 3.10 to 2.50 eV due to sub-bandgap defect states. Steady-state and time-resolved fluorescence spectra indicate enhanced radiative recombination and shorter carrier lifetimes, with the 20 s sample showing a lifetime of 548 ps. Notably, the 15 s film achieved outstanding NH<sub>3</sub> sensing performance, with rapid response (5.7 s), fast recovery (10.1 s), high selectivity, and humidity tolerance over 50 days. This work demonstrates that adsorption time in SILAR cycles can be systematically tuned to control ZnO film morphology, defect states, and photophysical dynamics. The optimized 15 s condition delivers record-high NH<sub>3</sub> response (5270 at 50 ppm) with long-term stability, establishing adsorption time as a simple yet powerful parameter for reproducible, high-performance ZnO gas sensors.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117567"},"PeriodicalIF":4.2,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Excitation and relaxation of bound excitons in Cu2O single crystal Cu2O单晶中束缚激子的激发和弛豫

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-26 DOI: 10.1016/j.optmat.2025.117564

L. Trinkler , D. Nilova , A. Sarakovskis , B. Berzina , L. Chang , M.M.C. Chou

{"title":"Excitation and relaxation of bound excitons in Cu2O single crystal","authors":"L. Trinkler , D. Nilova , A. Sarakovskis , B. Berzina , L. Chang , M.M.C. Chou","doi":"10.1016/j.optmat.2025.117564","DOIUrl":"10.1016/j.optmat.2025.117564","url":null,"abstract":"<div><div>Excitation and relaxation processes of photoluminescence from bound excitons were studied in (100) Cu<sub>2</sub>O single crystal under irradiation of the wavelength-tunable laser in the 10–300 K temperature range. PL emission bands at 1.72 eV, 1.53 eV and 1.36 eV, assigned to bound excitons localized at oxygen and copper vacancies <span><math><mrow><msubsup><mi>V</mi><mi>O</mi><mrow><mn>2</mn><mo>+</mo></mrow></msubsup></mrow></math></span>, <span><math><mrow><msubsup><mi>V</mi><mi>O</mi><mo>+</mo></msubsup></mrow></math></span>, <span><math><mrow><msub><mi>V</mi><mtext>Cu</mtext></msub></mrow></math></span>, correspondingly, are excited in the energy range 2.9–1.8 eV, covering regions of violet, blue, green and yellow excitons and a red band at 1.93 eV, assigned to the direct excitation of oxygen-vacancy-bound exciton. PL thermal decay curves have a non-monotonous character with signs of negative thermal quenching implying a complex process of bound exciton transfer between defect centres. For all bound exciton emission bands the obtained activation energies demonstrate dependence on excitation photon energy. The excitation energy dependence of the activation energy mirrors that of the PL intensity, suggesting a link between exciton density and thermal stability.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117564"},"PeriodicalIF":4.2,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Upconversion photoluminescence in WSSe alloy monolayer under uniaxial tensile strain 单轴拉伸应变下WSSe合金单层的上转换光致发光

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-26 DOI: 10.1016/j.optmat.2025.117563

Shrawan Roy , Jie Gao , Xiaodong Yang

引用次数: 0

Controlled copolymerization rate of 3-(4-fluorophenyl) thiophene monomer and EDOT for tunable multicolor electrochromic materials with excellent cycling stability 3-（4-氟苯基）噻吩单体与EDOT可调多色电致变色材料共聚速率控制，循环稳定性好

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-26 DOI: 10.1016/j.optmat.2025.117558

Sijia Wang , Pengju Wang , Zhaodi Lu , Yuanxu Rao , Ying Zhang , Anhang Zhou , Ruihui Peng , Xuyang Zhang , Nana Liu , Bo Wang , Guohua Wu

{"title":"Controlled copolymerization rate of 3-(4-fluorophenyl) thiophene monomer and EDOT for tunable multicolor electrochromic materials with excellent cycling stability","authors":"Sijia Wang , Pengju Wang , Zhaodi Lu , Yuanxu Rao , Ying Zhang , Anhang Zhou , Ruihui Peng , Xuyang Zhang , Nana Liu , Bo Wang , Guohua Wu","doi":"10.1016/j.optmat.2025.117558","DOIUrl":"10.1016/j.optmat.2025.117558","url":null,"abstract":"<div><div>Electrochromic materials featuring precisely controllable and tunable multicolor characteristics have generated widespread interest for a range of practical applications, owing to their adaptable functionality (e.g. smart windows, wearable electronics). Development of the electrochromic materials combining a diverse color gamut with high operational stability is still a major challenge. During electrochemical copolymerization, the rate of copolymerization was adjusted by altering the copolymerization ratios of the two monomers (3-(4-fluorophenyl) thiophene (FBTH) and 3,4-ethylenedioxythiophene (EDOT)), which in turn achieves a tunable multicolor. By adjusting the monomer copolymerization rate the copolymer films were prepared that displayed deep red, purplish red, bluish purple, blue, and dark blue in the neutral state, and all of them changed to light green or light blue after applying oxidation voltage. In addition, the variation of electrochemical and electrochromic properties of the copolymer film with the copolymerization rate of the FBTH and EDOT has been thoroughly investigated, and electrochromic materials with excellent overall performance have been obtained. The cycling stability of the polymer films was significantly improved by copolymerizing FBTH with a small percentage of EDOT (from 84 % after 50 cycles for FBTH-0 to 97 % after 500 cycles for FBTH-3). This study provides a feasible strategy for the preparation of tunable multicolor stabilized electrochromic materials for various electrochemical devices.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117558"},"PeriodicalIF":4.2,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultrafast excitation of nonlinear optical absorption and refraction in dual-emitting carbon dots at visible and NIR wavelengths 可见光和近红外双发射碳点非线性光学吸收和折射的超快激发

IF 4.2 3区材料科学

Optical Materials Pub Date : 2025-09-25 DOI: 10.1016/j.optmat.2025.117559

Aminakutty Neerkattil , Sreekanth Perumbilavil , Murukeshan Vadakke Matham , Jayeeta Bhattacharyya

{"title":"Ultrafast excitation of nonlinear optical absorption and refraction in dual-emitting carbon dots at visible and NIR wavelengths","authors":"Aminakutty Neerkattil , Sreekanth Perumbilavil , Murukeshan Vadakke Matham , Jayeeta Bhattacharyya","doi":"10.1016/j.optmat.2025.117559","DOIUrl":"10.1016/j.optmat.2025.117559","url":null,"abstract":"<div><div>Nonlinear optical properties of nanomaterials have attracted significant attention due to their critical role in advancing photonics, optoelectronics, and laser technologies. Carbon dots, a novel class of carbon-based nanomaterials, exhibit exceptional nonlinear optical behaviour, attributed to their unique structure and versatile surface functionalities. Unlike traditional semiconductors, carbon dots offer excellent photostability, tunable emission, environmentally friendly characteristics, and good biocompatibility, making them promising candidates for nonlinear optical studies. In this paper, we investigate the third-order nonlinear optical response of solution-dispersed dual-emitting carbon dots under ultrafast laser excitation at visible and near-infrared wavelengths using the single-beam z-scan technique. At an excitation wavelength of 515 nm, the dual-emitting carbon dots exhibit saturable absorption at low pulse energies and a combination of saturable absorption and two-photon absorption at higher pulse energies. Conversely, at an excitation wavelength of 1030 nm, the nonlinear optical response is dominated by two-photon absorption. Additionally, studies on the nonlinear refractive properties revealed that the sample exhibited positive nonlinear refraction (self-focusing) at both excitation wavelengths. Furthermore, we show that the nonlinear absorptive and refractive properties of these carbon dots are strongly solvent-dependent, with the strength of the nonlinear processes varying significantly based on the solvent polarity. These findings highlight the potential of synthesised dual-emitting carbon dots for broadband and tunable nonlinear optical applications. Since the same carbon dots behave differently with different dispersing solvents, they can be used as saturable absorbers, ultrafast optical limiters, and contrast agents for various bioimaging technologies.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"169 ","pages":"Article 117559"},"PeriodicalIF":4.2,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0