Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100730
Titanium dioxide (TiO2) has attracted much attention because of their desirable physicochemical properties especially in the water splitting process. In this work pure and Fe-doped TiO2 compounds are studies theoretically with the help of Generalized Gradient Approximation with the revised Pardew–Burke–Ernzerh (RPBE) exchange–correlation scheme. Total Density of States (TDOS) and Partial Density of States (DOS) were analyzed in detail which show that iron (Fe) and oxygen (O) orbitals hybridize, especially in the region of the doping system conduction band minima for both modes. Additionally, this interaction produces an energy level that effectively reduces the bandgap of the adsorbed system. Optical properties were elucidated which shows that Fe-doped TiO2 system results in high absorption and photoconductivity. Moreover, the results demonstrate low bandgap energy which is suitable for the reduction in water splitting without the need for external energy. Magnetic properties demonstrated that Fe-doped TiO2 systems show very low diamagnetic responses. The calculated elastic properties of Fe-doped TiO2 indicate ductile nature of the material with a strong average bond strength. Fe-doped TiO2 exhibited less microcracks with a mechanically stable composition.
{"title":"Atomistic modulating of structural, elastic, and optoelectronic behavior of pure TiO2 and Fe/TiO2 for photoelectrochemical water splitting application","authors":"","doi":"10.1016/j.rio.2024.100730","DOIUrl":"10.1016/j.rio.2024.100730","url":null,"abstract":"<div><p>Titanium dioxide (TiO<sub>2</sub>) has attracted much attention because of their desirable physicochemical properties especially in the water splitting process. In this work pure and Fe-doped TiO<sub>2</sub> compounds are studies theoretically with the help of Generalized Gradient Approximation with the revised Pardew–Burke–Ernzerh (RPBE) exchange–correlation scheme. Total Density of States (TDOS) and Partial Density of States (DOS) were analyzed in detail which show that iron (Fe) and oxygen (O) orbitals hybridize, especially in the region of the doping system conduction band minima for both modes. Additionally, this interaction produces an energy level that effectively reduces the bandgap of the adsorbed system. Optical properties were elucidated which shows that Fe-doped TiO<sub>2</sub> system results in high absorption and photoconductivity. Moreover, the results demonstrate low bandgap energy which is suitable for the reduction in water splitting without the need for external energy. Magnetic properties demonstrated that Fe-doped TiO<sub>2</sub> systems show very low diamagnetic responses. The calculated elastic properties of Fe-doped TiO<sub>2</sub> indicate ductile nature of the material with a strong average bond strength. Fe-doped TiO<sub>2</sub> exhibited less microcracks with a mechanically stable composition.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001275/pdfft?md5=2f2057f0b4202afa45d22fc949f74810&pid=1-s2.0-S2666950124001275-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141845459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100694
Silicon, traditionally known as an indirect band gap semiconductor, unveils intriguing properties at the nanoscale, stemming from deviations from k-conservation rules within nanostructures. In our study, we scrutinized four hydrogenated Si 0D-nanostructures—Si10H16, Si14H20, Si18H24, and Si22H28—to unravel their dynamic stability under thermal fluctuations and optical characteristics. We initiated our exploration by employing the TD-DFT framework to generate and analyze the optical properties of these geometrically optimized nanostructures. Simultaneously, we conducted ab initio molecular dynamics simulations to examine the structural robustness and thermal stability of the four structures. Leveraging the Car-Parrinello molecular dynamics approach within the Quantum ESPRESSO open software suite, we observed temperature evolution and stability differences among the nanostructures at targeted temperatures 40 and 300 K. Our subsequent investigation delved into the Turbo-Lanczos time-dependent DFT method, unraveling the optical properties and excited-state dynamics of hydrogenated Si nanostructures. The results unveiled shifts towards higher energy absorption edges E0, accompanied by alterations in the permittivity tensor, complex refractive index, oscillator strength, and reflectivity. Notably, the analysis revealed an enlarged HOMO-LUMO gap, distinctive from bulk Si. Furthermore, our models predicted the elimination of phase-dependent E1/E2 optical transition peaks in the imaginary part of the dielectric function, and a gradual decrease in the low-frequency dielectric response with increased hydrogenation of the amorphous structures. These findings underscore the promising applications of hydrogenating Si nanostructures in diverse technological domains such as optoelectronics, memristors, sensors, and quantum computing. Their tunable optical properties, size-dependent behaviors, and compatibility with existing silicon-based devices make them particularly appealing for next-generation technologies.
硅历来被认为是一种间接带隙半导体,但在纳米尺度上,它却因偏离了纳米结构中的 k 保留规则而展现出了引人入胜的特性。在我们的研究中,我们仔细研究了四种氢化硅 0D 纳米结构--Si10H16、Si14H20、Si18H24 和 Si22H28,以揭示它们在热波动下的动态稳定性和光学特性。我们首先采用 TD-DFT 框架来生成和分析这些几何优化纳米结构的光学特性。同时,我们还进行了 ab initio 分子动力学模拟,以检验这四种结构的结构稳健性和热稳定性。利用量子 ESPRESSO 开放软件套件中的 Car-Parrinello 分子动力学方法,我们观察了纳米结构在目标温度 40 和 300 K 时的温度演变和稳定性差异。研究结果表明,氢化硅纳米结构向更高能量的吸收边缘 E0 移动,并伴随着介电常数张量、复折射率、振荡器强度和反射率的变化。值得注意的是,分析表明 HOMO-LUMO 间隙增大,与块状硅截然不同。此外,根据我们的模型预测,介电函数虚部中与相位相关的 E1/E2 光学转变峰会消失,而且随着非晶结构氢化程度的增加,低频介电响应会逐渐降低。这些发现强调了氢化硅纳米结构在光电子学、忆阻器、传感器和量子计算等不同技术领域的应用前景。这些纳米结构具有可调的光学特性、与尺寸相关的行为以及与现有硅基器件的兼容性,因此对下一代技术特别有吸引力。
{"title":"A holistic understanding of optical properties in amorphous H-terminated Si-nanostructures: Combining TD-DFT with AIMD","authors":"","doi":"10.1016/j.rio.2024.100694","DOIUrl":"10.1016/j.rio.2024.100694","url":null,"abstract":"<div><p>Silicon, traditionally known as an indirect band gap semiconductor, unveils intriguing properties at the nanoscale, stemming from deviations from k-conservation rules within nanostructures. In our study, we scrutinized four hydrogenated Si 0D-nanostructures—Si<sub>10</sub>H<sub>16</sub>, Si<sub>14</sub>H<sub>20</sub>, Si<sub>18</sub>H<sub>24</sub>, and Si<sub>22</sub>H<sub>28</sub>—to unravel their dynamic stability under thermal fluctuations and optical characteristics. We initiated our exploration by employing the TD-DFT framework to generate and analyze the optical properties of these geometrically optimized nanostructures. Simultaneously, we conducted ab initio molecular dynamics simulations to examine the structural robustness and thermal stability of the four structures. Leveraging the Car-Parrinello molecular dynamics approach within the Quantum ESPRESSO open software suite, we observed temperature evolution and stability differences among the nanostructures at targeted temperatures 40 and 300 K. Our subsequent investigation delved into the Turbo-Lanczos time-dependent DFT method, unraveling the optical properties and excited-state dynamics of hydrogenated Si nanostructures. The results unveiled shifts towards higher energy absorption edges E<sub>0</sub>, accompanied by alterations in the permittivity tensor, complex refractive index, oscillator strength, and reflectivity. Notably, the analysis revealed an enlarged HOMO-LUMO gap, distinctive from bulk Si. Furthermore, our models predicted the elimination of phase-dependent E<sub>1</sub>/E<sub>2</sub> optical transition peaks in the imaginary part of the dielectric function, and a gradual decrease in the low-frequency dielectric response with increased hydrogenation of the amorphous structures. These findings underscore the promising applications of hydrogenating Si nanostructures in diverse technological domains such as optoelectronics, memristors, sensors, and quantum computing. Their tunable optical properties, size-dependent behaviors, and compatibility with existing silicon-based devices make them particularly appealing for next-generation technologies.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124000919/pdfft?md5=4bf3d55996d866e8ab8438667092ded7&pid=1-s2.0-S2666950124000919-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141139956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100735
In this study, WO3/Ag/W/WO3 (WAWW) films were deposited at room temperature on a B270 glass substrate from W and Ag targets using a radiofrequency magnetron reactive sputtering system. The influence of the thin tungsten interlayer on the electrical and optical properties of the WAWW layer structure was investigated through ellipsometry, a four-point probe and a spectrophotometer. It was determined that the thin tungsten interlayer effectively prevented the oxidation of the silver film. The WAWW film had a dielectric-metal-dielectric (DMD) layered structure with good electrical conductivity and high visible transmittance. The tungsten layer was no more than 2-nm thick. The sheet resistance and luminous transmittance of the WO3(29.5 nm)/Ag(14.2 nm)/W(2 nm)/WO3(68.6 nm) film were 4.64 Ω/sq and 65.4 %, respectively. Based on the WAWW four-layer structure, stacked WO3(29.5 nm)/Ag(14.2 nm)/W(2 nm)/WO3(68.6 nm)/Ag(16.9 nm)/W(2 nm)/WO3(30.4 nm) seven-layer structures deposited on B270 glass substrates were used for both ITO-free electrochromic and hot mirror applications. The visible (400–700 nm) and NIR (700–1200 nm) transmittance values of the bleached WAWW seven-layer structure were 71.5 % and 9.9 %, respectively. The visible transmittance of the colored WAWW seven-layer structure was 23.6 %. Finally, the bi-layer WAWW films were used to obtain an ITO-free WAWW seven-layer structure with a good electrochromic and optical performance.
{"title":"Fabrication of a hot mirror using ITO-free electrochromic films","authors":"","doi":"10.1016/j.rio.2024.100735","DOIUrl":"10.1016/j.rio.2024.100735","url":null,"abstract":"<div><p>In this study, WO<sub>3</sub>/Ag/W/WO<sub>3</sub> (WAWW) films were deposited at room temperature on a B270 glass substrate from W and Ag targets using a radiofrequency magnetron reactive sputtering system. The influence of the thin tungsten interlayer on the electrical and optical properties of the WAWW layer structure was investigated through ellipsometry, a four-point probe and a spectrophotometer. It was determined that the thin tungsten interlayer effectively prevented the oxidation of the silver film. The WAWW film had a dielectric-metal-dielectric (DMD) layered structure with good electrical conductivity and high visible transmittance. The tungsten layer was no more than 2-nm thick. The sheet resistance and luminous transmittance of the WO<sub>3</sub>(29.5 nm)/Ag(14.2 nm)/W(2 nm)/WO<sub>3</sub>(68.6 nm) film were 4.64 Ω/sq and 65.4 %, respectively. Based on the WAWW four-layer structure, stacked WO<sub>3</sub>(29.5 nm)/Ag(14.2 nm)/W(2 nm)/WO<sub>3</sub>(68.6 nm)/Ag(16.9 nm)/W(2 nm)/WO<sub>3</sub>(30.4 nm) seven-layer structures deposited on B270 glass substrates were used for both ITO-free electrochromic and hot mirror applications. The visible (400–700 nm) and NIR (700–1200 nm) transmittance values of the bleached WAWW seven-layer structure were 71.5 % and 9.9 %, respectively. The visible transmittance of the colored WAWW seven-layer structure was 23.6 %. Finally, the bi-layer WAWW films were used to obtain an ITO-free WAWW seven-layer structure with a good electrochromic and optical performance.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001329/pdfft?md5=561d996ca8def2e41e1e3dd140f48e84&pid=1-s2.0-S2666950124001329-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100718
Mahdi Rahmanpour, Alireza Erfanian, Ahmad Afifi, Mahdi Khaje, Mohammad Hossein Fahimifar
The most important goal of quantum communication is to distribute the encryption key between the transmitter and the receiver. The optimal situation in Quantum Key Distribution (QKD) between transmitter and receiver is to increase the key distribution rate per second, increase the transmission distance, and reduce the error in key distribution. Several protocols used for QKD. The most important of QKD protocols is the BB84. One of the challenges leading to errors in quantum protocols is generating error pulses in single-photon detectors. These pulses caused by the inherent effects of quantum devices. They can cause wrong detection in the receiver. Many measures have been taken in the design and construction of single-photon detectors to reduce this error pulses, but it is not possible to eliminate all of them. Afterpulse and dark counts are two types of unwanted pulses that occur with single-photon detectors. In this paper, a new QKD protocol is proposed. It is an upgrade of the BB84 protocol and can reduce the effects of unwanted pulses such as afterpulse and dark counts in QKD avalanche detectors.
{"title":"A new quantum key distribution protocol to reduce afterpulse and dark counts effects","authors":"Mahdi Rahmanpour, Alireza Erfanian, Ahmad Afifi, Mahdi Khaje, Mohammad Hossein Fahimifar","doi":"10.1016/j.rio.2024.100718","DOIUrl":"https://doi.org/10.1016/j.rio.2024.100718","url":null,"abstract":"<div><p>The most important goal of quantum communication is to distribute the encryption key between the transmitter and the receiver. The optimal situation in Quantum Key Distribution (QKD) between transmitter and receiver is to increase the key distribution rate per second, increase the transmission distance, and reduce the error in key distribution. Several protocols used for QKD. The most important of QKD protocols is the BB84. One of the challenges leading to errors in quantum protocols is generating error pulses in single-photon detectors. These pulses caused by the inherent effects of quantum devices. They can cause wrong detection in the receiver. Many measures have been taken in the design and construction of single-photon detectors to reduce this error pulses, but it is not possible to eliminate all of them. Afterpulse and dark counts are two types of unwanted pulses that occur with single-photon detectors. In this paper, a new QKD protocol is proposed. It is an upgrade of the BB84 protocol and can reduce the effects of unwanted pulses such as afterpulse and dark counts in QKD avalanche detectors.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001159/pdfft?md5=2af2b22cbc800fc0a6a3a73640493dca&pid=1-s2.0-S2666950124001159-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100723
Varsha, Gautam Das
This article experimentally demonstrates the generation of mode-locked (ML) pulses, which can operate either at 1568 nm or 1608 nm in an Erbium/Ytterbium co-doped fiber laser cavity (EYDF). The wavelength switching was achieved by adjusting the cavity loss. Depending on the cavity length and losses, the laser could operate in either mode-locked (ML) or Q-switched (QS) regimes. We explored the characteristics of the QS and ML pulses, based on the pump power, cavity length and loss. The laser produced stable QS pulses with a repetition rate of 22.73 kHz and a width of 12.2 μs at a pump power of 3.1 W at 1608 nm, for a 30 m long cavity. The laser produced 520 ns ML pulses at 1568 nm with a repetition rate of 877 kHz, average output power of 2.15 mW, and energy of 2.45 nJ with an additional single-mode fiber (SMF) length 200 m at the same pump power. The laser could switch to 1608 nm wavelength when the cavity losses were adjusted.
{"title":"Generation of wavelength-switchable nanosecond mode-locked pulses in an Erbium/Ytterbium co-doped fiber laser cavity","authors":"Varsha, Gautam Das","doi":"10.1016/j.rio.2024.100723","DOIUrl":"https://doi.org/10.1016/j.rio.2024.100723","url":null,"abstract":"<div><p>This article experimentally demonstrates the generation of mode-locked (ML) pulses, which can operate either at 1568 nm or 1608 nm in an Erbium/Ytterbium co-doped fiber laser cavity (EYDF). The wavelength switching was achieved by adjusting the cavity loss. Depending on the cavity length and losses, the laser could operate in either mode-locked (ML) or Q-switched (QS) regimes. We explored the characteristics of the QS and ML pulses, based on the pump power, cavity length and loss. The laser produced stable QS pulses with a repetition rate of 22.73 kHz and a width of 12.2 μs at a pump power of 3.1 W at 1608 nm, for a 30 m long cavity. The laser produced 520 ns ML pulses at 1568 nm with a repetition rate of 877 kHz, average output power of 2.15 mW, and energy of 2.45 nJ with an additional single-mode fiber (SMF) length 200 m at the same pump power. The laser could switch to 1608 nm wavelength when the cavity losses were adjusted.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001202/pdfft?md5=289c0622cd79643b6f66f6a6481f8746&pid=1-s2.0-S2666950124001202-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100734
Sb2Se3 has a high absorption coefficient of 105 cm−1 in the visible light range, which is an excellent absorber layer material. Currently, a better band alignment between conventional CdS and Sb2Se3 has led to the widespread adoption of CdS as the electron transport layer (ETL) in Sb2Se3 solar cells. However, CdS is toxic, necessitating the exploration of alternative ETL materials that are eco-friendly and possess an appropriate energy band with Sb2Se3. In this study, we endeavor to pioneer an all-inorganic, green solar cell structure of Au/MoS2/Sb2Se3/WS2/ITO by employing MoS2 as the hole transport layer (HTL) and WS2 as the ETL. We primarily optimized Sb2Se3 thickness and its hole doping concentration (NA) by SCAPS-1D numerical simulation. Based on the analysis of built-in electric field and carrier recombination rate along Sb2Se3, the optimal thickness and NA ranges of Sb2Se3 are determined, which are 0.9–1.1 μm and 1016-1018 cm−3 respectively. Through a series of optimization, the structure achieves the highest power conversion efficiency (PCE) of about 25.3 % in the current simulation of Sb2Se3 solar cells. After comparing the novel WS2 ETL with the conventional CdS ETL, we find that WS2 has a larger built-in potential (Vbi) and charge recombination resistance (Rrec). In addition, from the analysis of energy band structure, the spike-like band at Sb2Se3/WS2 interface can effectively inhibit the carrier recombination, which makes the device obtain a larger open circuit voltage (VOC) of 0.69 V. This study can provide theoretical reference for the development of non-toxic and efficient Sb2Se3 solar cells.
{"title":"Analysis and design of 25.3% efficient Sb2Se3 solar cells by numerical simulation","authors":"","doi":"10.1016/j.rio.2024.100734","DOIUrl":"10.1016/j.rio.2024.100734","url":null,"abstract":"<div><p>Sb<sub>2</sub>Se<sub>3</sub> has a high absorption coefficient of 10<sup>5</sup> cm<sup>−1</sup> in the visible light range, which is an excellent absorber layer material. Currently, a better band alignment between conventional CdS and Sb<sub>2</sub>Se<sub>3</sub> has led to the widespread adoption of CdS as the electron transport layer (ETL) in Sb<sub>2</sub>Se<sub>3</sub> solar cells. However, CdS is toxic, necessitating the exploration of alternative ETL materials that are eco-friendly and possess an appropriate energy band with Sb<sub>2</sub>Se<sub>3</sub>. In this study, we endeavor to pioneer an all-inorganic, green solar cell structure of Au/MoS<sub>2</sub>/Sb<sub>2</sub>Se<sub>3</sub>/WS<sub>2</sub>/ITO by employing MoS<sub>2</sub> as the hole transport layer (HTL) and WS<sub>2</sub> as the ETL. We primarily optimized Sb<sub>2</sub>Se<sub>3</sub> thickness and its hole doping concentration (N<sub>A</sub>) by SCAPS-1D numerical simulation. Based on the analysis of built-in electric field and carrier recombination rate along Sb<sub>2</sub>Se<sub>3</sub>, the optimal thickness and N<sub>A</sub> ranges of Sb<sub>2</sub>Se<sub>3</sub> are determined, which are 0.9–1.1 μm and 10<sup>16</sup>-10<sup>18</sup> cm<sup>−3</sup> respectively. Through a series of optimization, the structure achieves the highest power conversion efficiency (PCE) of about 25.3 % in the current simulation of Sb<sub>2</sub>Se<sub>3</sub> solar cells. After comparing the novel WS<sub>2</sub> ETL with the conventional CdS ETL, we find that WS<sub>2</sub> has a larger built-in potential (V<sub>bi</sub>) and charge recombination resistance (R<sub>rec</sub>). In addition, from the analysis of energy band structure, the spike-like band at Sb<sub>2</sub>Se<sub>3</sub>/WS<sub>2</sub> interface can effectively inhibit the carrier recombination, which makes the device obtain a larger open circuit voltage (V<sub>OC</sub>) of 0.69 V. This study can provide theoretical reference for the development of non-toxic and efficient Sb<sub>2</sub>Se<sub>3</sub> solar cells.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001317/pdfft?md5=f89c34a33d1fb44e1cc50f48ffdb0f24&pid=1-s2.0-S2666950124001317-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142075846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100737
We investigated the optical properties and thermal conductivity of blade-coated graphene quantum dots (GQDs)/PEDOT:PSS hybrid thin films by varying the content of GQDs. The optical properties were determined by spectroscopic ellipsometry in the range of 1.2–5.5 eV. Two dispersion models were used to analyze the optical properties of the films: the Bruggeman effective medium approximation (BEMA) for the hybrid films, and the Drude model combined with a Lorentzian oscillator for both the pure and the hybrid films, which provides insight into their electrical properties. As a novel finding, we observed that the optical anisotropy of PEDOT:PSS (Aldrich 483095) films is reduced after incorporating GQDs. Moreover, dedoping of the PEDOT chains is demonstrated upon increasing the content of GQDs within the hybrid films. Furthermore, the thermal conductivity shows a two-fold decrease as the GQDs fraction increases from 0 to 10 wt%. This result is understood considering that the GQDs act as local scattering centers, resulting in a decrease of the thermal conductivity.
{"title":"Impacts of graphene quantum dots on the optical, electrical and thermal properties of the archetypal conducting polymer PEDOT:PSS","authors":"","doi":"10.1016/j.rio.2024.100737","DOIUrl":"10.1016/j.rio.2024.100737","url":null,"abstract":"<div><p>We investigated the optical properties and thermal conductivity of blade-coated graphene quantum dots (GQDs)/PEDOT:PSS hybrid thin films by varying the content of GQDs. The optical properties were determined by spectroscopic ellipsometry in the range of 1.2–5.5 eV. Two dispersion models were used to analyze the optical properties of the films: the Bruggeman effective medium approximation (BEMA) for the hybrid films, and the Drude model combined with a Lorentzian oscillator for both the pure and the hybrid films, which provides insight into their electrical properties. As a novel finding, we observed that the optical anisotropy of PEDOT:PSS (Aldrich 483095) films is reduced after incorporating GQDs. Moreover, dedoping of the PEDOT chains is demonstrated upon increasing the content of GQDs within the hybrid films. Furthermore, the thermal conductivity shows a two-fold decrease as the GQDs fraction increases from 0 to 10 wt%. This result is understood considering that the GQDs act as local scattering centers, resulting in a decrease of the thermal conductivity.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001342/pdfft?md5=76c7e848260be884eb2776474d4fb3a6&pid=1-s2.0-S2666950124001342-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142096563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100736
The escalating environmental concerns associated with plastic waste have intensified the search for sustainable waste management solutions. Plastic dispersion in the environment poses severe threats to ecosystems, human well-being, and agriculture. Consequently, addressing plastic pollution stands as a pressing ecological concern. In contrast, the adoption of sustainable solar energy is harnessed for the production of HHO (Oxy-Hydrogen) gas, offering a promising avenue for clean energy generation. Gas production is achieved through the process of electrolysis, utilizing solar panels as the primary energy source. To address storage challenges, a spiral pipe configuration is employed for the interim containment of the generated HHO gas. Given the highly flammable nature of HHO gas, stringent safety protocols are imperative throughout the production and storage phases. To ensure the safe handling of HHO gas, a sophisticated MQ-8 Sensor is employed for real-time leak detection within the gas containment system. This sensor plays a critical role in maintaining operational safety by promptly identifying and addressing any potential gas leaks that may arise within the tubing infrastructure. The HHO gas, generated through the electrolysis process, serves as the primary fuel for the pyrolysis of plastic. This optimization is crucial to maximize the efficiency of the pyrolysis process. As a result of the pyrolysis process, crude oil is produced as an intermediary product. This crude oil holds the potential for subsequent refinement, offering versatility for various applications and end uses. Hence, the integration of solar energy-driven HHO gas in the pyrolysis of plastic demonstrates a promising avenue for mitigating plastic waste and contributing to environmental cleanliness. The intricate technological aspects, ranging from gas production through electrolysis, leak detection, optimized combustion, to crude oil production and refinement, collectively establish a comprehensive framework for sustainable waste management and resource recovery.
{"title":"Experimental investigation on a solar-powered oxy-hydrogen gas system for enhanced plastic pyrolysis","authors":"","doi":"10.1016/j.rio.2024.100736","DOIUrl":"10.1016/j.rio.2024.100736","url":null,"abstract":"<div><p>The escalating environmental concerns associated with plastic waste have intensified the search for sustainable waste management solutions. Plastic dispersion in the environment poses severe threats to ecosystems, human well-being, and agriculture. Consequently, addressing plastic pollution stands as a pressing ecological concern. In contrast, the adoption of sustainable solar energy is harnessed for the production of HHO (Oxy-Hydrogen) gas, offering a promising avenue for clean energy generation. Gas production is achieved through the process of electrolysis, utilizing solar panels as the primary energy source. To address storage challenges, a spiral pipe configuration is employed for the interim containment of the generated HHO gas. Given the highly flammable nature of HHO gas, stringent safety protocols are imperative throughout the production and storage phases. To ensure the safe handling of HHO gas, a sophisticated MQ-8 Sensor is employed for real-time leak detection within the gas containment system. This sensor plays a critical role in maintaining operational safety by promptly identifying and addressing any potential gas leaks that may arise within the tubing infrastructure. The HHO gas, generated through the electrolysis process, serves as the primary fuel for the pyrolysis of plastic. This optimization is crucial to maximize the efficiency of the pyrolysis process. As a result of the pyrolysis process, crude oil is produced as an intermediary product. This crude oil holds the potential for subsequent refinement, offering versatility for various applications and end uses. Hence, the integration of solar energy-driven HHO gas in the pyrolysis of plastic demonstrates a promising avenue for mitigating plastic waste and contributing to environmental cleanliness. The intricate technological aspects, ranging from gas production through electrolysis, leak detection, optimized combustion, to crude oil production and refinement, collectively establish a comprehensive framework for sustainable waste management and resource recovery.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001330/pdfft?md5=39cbcd76f4b1940b0485537d972a5699&pid=1-s2.0-S2666950124001330-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142129108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100732
We present the design and the experimental characterization of a miniature “portable” mini-endoscope with a large field-of-view () that operates with two spectral bands adapted for mCherry (peak emission at 610 nm) and GCaMP6s (peak emission at 513 nm) fluorophores. The diameter of the implant is very small (0.5 mm), the total weight is 1.8 g, the size is , and the lateral resolution of the device is . This compact and lightweight system allows investigation of the neural activity of two different neuronal populations.
{"title":"Lightweight mini-endoscope for two color imaging of neural activities with large field of view","authors":"","doi":"10.1016/j.rio.2024.100732","DOIUrl":"10.1016/j.rio.2024.100732","url":null,"abstract":"<div><p>We present the design and the experimental characterization of a miniature “portable” mini-endoscope with a large field-of-view (<span><math><mrow><mo>≈</mo><mn>360</mn><mspace></mspace><mi>r</mi><mi>m</mi><mi>m</mi><mi>u</mi><mi>m</mi></mrow></math></span>) that operates with two spectral bands adapted for mCherry (peak emission at 610 nm) and GCaMP6s (peak emission at 513 nm) fluorophores. The diameter of the implant is very small (0.5 mm), the total weight is 1.8 g, the size is <span><math><mrow><mn>10</mn><mo>×</mo><mn>12</mn><mo>×</mo><mn>21</mn><mspace></mspace><msup><mrow><mi>mm</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span>, and the lateral resolution of the device is <span><math><mrow><mo>≈</mo><mn>4</mn><mo>.</mo><mn>5</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>. This compact and lightweight system allows investigation of the neural activity of two different neuronal populations.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001299/pdfft?md5=dfd8bef8682797d20f316116ac4d415a&pid=1-s2.0-S2666950124001299-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.rio.2024.100714
I. Cázares-Aguilar , J.C. Atenco , P. Martínez-Vara , F. Cubillos-Morales , I. Julián-Macías , G. Martínez-Niconoff
The synthesis of optical fields that follows a stochastic process and whose statistical mean values generate the self-imaging-revivals effect is analyzed. A sufficient condition for optical fields to exhibit the self-imaging effect occurs when the frequency representation is located on the Montgomery’s rings. The study is performed by implementing stationary random fluctuations on the Montgomery’s rings of additive and multiplicative types. The additive noise is of the stochastic radial walk type with zero mean. Multiplicative noise generates stochastic angular fluctuations in the rings and is implemented using the Karhunen–Loève theorem. The modal representation implicit in the theorem is obtained by interpreting the self-imaging planes as an optical cavity, assuring the statistical periodicity of the noise. A time consonance of the random fluctuations for each ring allows to determine the revivals period for the self-imaging optical fields. The model is corroborated by computer simulations.
{"title":"Stochastic modulation of the Montgomery’s rings to generate the self-imaging effect with revival features","authors":"I. Cázares-Aguilar , J.C. Atenco , P. Martínez-Vara , F. Cubillos-Morales , I. Julián-Macías , G. Martínez-Niconoff","doi":"10.1016/j.rio.2024.100714","DOIUrl":"https://doi.org/10.1016/j.rio.2024.100714","url":null,"abstract":"<div><p>The synthesis of optical fields that follows a stochastic process and whose statistical mean values generate the self-imaging-revivals effect is analyzed. A sufficient condition for optical fields to exhibit the self-imaging effect occurs when the frequency representation is located on the Montgomery’s rings. The study is performed by implementing stationary random fluctuations on the Montgomery’s rings of additive and multiplicative types. The additive noise is of the stochastic radial walk type with zero mean. Multiplicative noise generates stochastic angular fluctuations in the rings and is implemented using the Karhunen–Loève theorem. The modal representation implicit in the theorem is obtained by interpreting the self-imaging planes as an optical cavity, assuring the statistical periodicity of the noise. A time consonance of the random fluctuations for each ring allows to determine the revivals period for the self-imaging optical fields. The model is corroborated by computer simulations.</p></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666950124001111/pdfft?md5=1ae0c5e011b65ff5eaa4c663d89eabdf&pid=1-s2.0-S2666950124001111-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}