L. Johnson, D. Elder, Huajun Xu, S. Hammond, Stephanie J. Benight, K. O'Malley, B. Robinson, L. Dalton
We review recent transformative advances in materials design, synthesis, and processing as well as device engineering for the utilization of organic materials in hybrid electro-optic (EO) and optical rectification (OR) technologies relevant to telecommunications, sensing, and computing. End-to-end (from molecules to systems) modeling methods utilizing multi-scale computation and theory permit prediction of the performance of novel materials in nanoscale device architectures including those involving plasmonic phenomena and architectures in which interfacial effects play a dominant role. Both EO and OR phenomenon require acentric organization of constituent active molecules. The incumbent methodology for achieving such organization is electric field poling, where chromophore shape, dipole moment, and conformational flexibility play dominant roles. Optimized chromophore design and control of the poling process has already led to record-setting advances in electro-optic performance, e.g., voltage-length performance of < 50 volt-micrometer, bandwidths < 500 GHz, and energy efficiency < 70 attojoule/bit. They have also led to increased thermal stability, low insertion loss and high signal quality (BER and SFDR). However, the limits of poling in the smallest nanophotonic devices—in which extraordinary optical field densities can be achieved—has stimulated development of alternatives based on covalent coupling of modern high-performance chromophores into ordered nanostructures. Covalent coupling enables higher performance, greater scalability, and greater stability and is especially suited for the latest nanoscale architectures. Recent developments in materials also facilitate a new technology—transparent photodetection based on optical rectification. OR does not involve electronic excitation, as is the case with conventional photodiodes, and as such represents a novel detection mechanism with a greatly reduced noise floor. OR already dominates at THz frequencies and recent advances will enable superior performance at GHz frequencies as well.
{"title":"New paradigms in materials and devices for hybrid electro-optics and optical rectification","authors":"L. Johnson, D. Elder, Huajun Xu, S. Hammond, Stephanie J. Benight, K. O'Malley, B. Robinson, L. Dalton","doi":"10.1117/12.2595638","DOIUrl":"https://doi.org/10.1117/12.2595638","url":null,"abstract":"We review recent transformative advances in materials design, synthesis, and processing as well as device engineering for the utilization of organic materials in hybrid electro-optic (EO) and optical rectification (OR) technologies relevant to telecommunications, sensing, and computing. End-to-end (from molecules to systems) modeling methods utilizing multi-scale computation and theory permit prediction of the performance of novel materials in nanoscale device architectures including those involving plasmonic phenomena and architectures in which interfacial effects play a dominant role. Both EO and OR phenomenon require acentric organization of constituent active molecules. The incumbent methodology for achieving such organization is electric field poling, where chromophore shape, dipole moment, and conformational flexibility play dominant roles. Optimized chromophore design and control of the poling process has already led to record-setting advances in electro-optic performance, e.g., voltage-length performance of < 50 volt-micrometer, bandwidths < 500 GHz, and energy efficiency < 70 attojoule/bit. They have also led to increased thermal stability, low insertion loss and high signal quality (BER and SFDR). However, the limits of poling in the smallest nanophotonic devices—in which extraordinary optical field densities can be achieved—has stimulated development of alternatives based on covalent coupling of modern high-performance chromophores into ordered nanostructures. Covalent coupling enables higher performance, greater scalability, and greater stability and is especially suited for the latest nanoscale architectures. Recent developments in materials also facilitate a new technology—transparent photodetection based on optical rectification. OR does not involve electronic excitation, as is the case with conventional photodiodes, and as such represents a novel detection mechanism with a greatly reduced noise floor. OR already dominates at THz frequencies and recent advances will enable superior performance at GHz frequencies as well.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133350163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Thapa, O. Iadlovska, H. Bisoyi, D. Paterson, J. Storey, C. Imrie, Quan Li, S. Shiyanovskii, O. Lavrentovich
An oblique helicoidal cholesteric ChOH represents a unique optical material with a pitch that can be tuned by an electric or magnetic field in a broad range from sub micrometers to micrometers. In this work, we demonstrate that the oblique helicoidal cholesteric doped with azoxybenzene molecules and stabilized by an electric field could also be tuned by light irradiation. At a fixed voltage, UV irradiation causes a redshift of the reflection peak by more than 200 nm. The demonstrated effect has the potential for applications such as smart windows, sensors, tunable lasers, and filters.
{"title":"Photocontrol of selective light reflection by oblique helicoidal cholesteric","authors":"K. Thapa, O. Iadlovska, H. Bisoyi, D. Paterson, J. Storey, C. Imrie, Quan Li, S. Shiyanovskii, O. Lavrentovich","doi":"10.1117/12.2592765","DOIUrl":"https://doi.org/10.1117/12.2592765","url":null,"abstract":"An oblique helicoidal cholesteric ChOH represents a unique optical material with a pitch that can be tuned by an electric or magnetic field in a broad range from sub micrometers to micrometers. In this work, we demonstrate that the oblique helicoidal cholesteric doped with azoxybenzene molecules and stabilized by an electric field could also be tuned by light irradiation. At a fixed voltage, UV irradiation causes a redshift of the reflection peak by more than 200 nm. The demonstrated effect has the potential for applications such as smart windows, sensors, tunable lasers, and filters.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132725032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While the narrow emission spectrum and high quantum yield of quantum dots (QDs) is desirable for light emitting devices (LEDs), the mechanisms that limit electroluminescent QDLED stability must be understood before they can be used in high brightness applications. The deep energy levels of Cd-based QDs allow for relatively easy electron injection but comparably difficult hole injection, resulting in an imbalance of charge carriers in the emission layer (EML) that can reduce efficiency via non-radiative recombination. The incorporation of a multi-component hole transport layer (HTL) consisting of materials with sequentially deeper highest occupied molecular orbital (HOMO) energy levels in a cascading HTL (CHTL) architecture has been shown to improve QDLED lifetime by 20x while also enhancing luminous efficiency. Prompt and delayed electrical and spectroscopic measurements indicate that the CHTL structure shifts excessive hole accumulation away from the QD/HTL interface, resulting in less degradation of the HTL in contact with the QD EML, and reduces leakage current by blocking electron transport to the anode. The trade-off between exciton density in the HTL vs. QDLED efficiency and stability highlights the importance of the HTL in long-term device performance.
{"title":"The influence of charge carriers in the hole transport layer on stability of quantum dot light-emitting devices","authors":"Tyler Davidson-Hall, H. Aziz","doi":"10.1117/12.2597418","DOIUrl":"https://doi.org/10.1117/12.2597418","url":null,"abstract":"While the narrow emission spectrum and high quantum yield of quantum dots (QDs) is desirable for light emitting devices (LEDs), the mechanisms that limit electroluminescent QDLED stability must be understood before they can be used in high brightness applications. The deep energy levels of Cd-based QDs allow for relatively easy electron injection but comparably difficult hole injection, resulting in an imbalance of charge carriers in the emission layer (EML) that can reduce efficiency via non-radiative recombination. The incorporation of a multi-component hole transport layer (HTL) consisting of materials with sequentially deeper highest occupied molecular orbital (HOMO) energy levels in a cascading HTL (CHTL) architecture has been shown to improve QDLED lifetime by 20x while also enhancing luminous efficiency. Prompt and delayed electrical and spectroscopic measurements indicate that the CHTL structure shifts excessive hole accumulation away from the QD/HTL interface, resulting in less degradation of the HTL in contact with the QD EML, and reduces leakage current by blocking electron transport to the anode. The trade-off between exciton density in the HTL vs. QDLED efficiency and stability highlights the importance of the HTL in long-term device performance.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116143278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic field-effect transistors (OFETs) have found a wide range of uses due to their attractive properties. A great deal of effort has been expended on boosting their mobilities, which tend to be low. Given this, accurate estimation of the mobility is crucial. We have developed a web application that automates or simplifies several of the steps required to estimate the mobility from experimental data. The app can be accessed at ofetanalysisapp.shinyapps.io/ofetanalysisapp. The app takes as inputs a file with the data and pieces of information like the number of OFETs and their channel lengths. The app has features that enable the user to mark OFETs as outliers, which are excluded from subsequent calculations. It fits nonlinear regression models to compute estimates of the mobility as well as the threshold voltage. The app provides several visualizations that give the user insight into the nature of the data. The estimates computed by the app can be downloaded in an Excel file so the user can perform further analysis. The use of the app is illustrated with a dataset from one of our OFET experiments.
{"title":"A new approach to transfer characteristic slope estimation","authors":"Vishash Verma, Drona Dahal, Raj Kishen Radha Krishnan, B. Lüssem, Tsung-Heng Tsai","doi":"10.1117/12.2593301","DOIUrl":"https://doi.org/10.1117/12.2593301","url":null,"abstract":"Organic field-effect transistors (OFETs) have found a wide range of uses due to their attractive properties. A great deal of effort has been expended on boosting their mobilities, which tend to be low. Given this, accurate estimation of the mobility is crucial. We have developed a web application that automates or simplifies several of the steps required to estimate the mobility from experimental data. The app can be accessed at ofetanalysisapp.shinyapps.io/ofetanalysisapp. The app takes as inputs a file with the data and pieces of information like the number of OFETs and their channel lengths. The app has features that enable the user to mark OFETs as outliers, which are excluded from subsequent calculations. It fits nonlinear regression models to compute estimates of the mobility as well as the threshold voltage. The app provides several visualizations that give the user insight into the nature of the data. The estimates computed by the app can be downloaded in an Excel file so the user can perform further analysis. The use of the app is illustrated with a dataset from one of our OFET experiments.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130411123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, optoelectronic devices are implemented based on natural DNA with enhanced performance and efficiency. In this study, we present stimulus pulse-dependent responses in natural DNA biopolymer devices. The device consists of a simple sandwich structure and the resistivity can be manipulated with respect to voltage operation. We characterize the stimulus pulse-dependent responses, where the synaptic plasticity will be presented. To further explore dynamics of resistive states, the effect of incorporating a photo-responsive material on the light-triggered electrical characteristics will be discussed. Our results reveal natural DNA biopolymer shows great promise for the development of synaptic devices for neuromorphic circuitry.
{"title":"Stimulus pulse-dependent responses in natural DNA biopolymer devices","authors":"Yu Lin, C. Cheng, Y. Hung","doi":"10.1117/12.2593450","DOIUrl":"https://doi.org/10.1117/12.2593450","url":null,"abstract":"In recent years, optoelectronic devices are implemented based on natural DNA with enhanced performance and efficiency. In this study, we present stimulus pulse-dependent responses in natural DNA biopolymer devices. The device consists of a simple sandwich structure and the resistivity can be manipulated with respect to voltage operation. We characterize the stimulus pulse-dependent responses, where the synaptic plasticity will be presented. To further explore dynamics of resistive states, the effect of incorporating a photo-responsive material on the light-triggered electrical characteristics will be discussed. Our results reveal natural DNA biopolymer shows great promise for the development of synaptic devices for neuromorphic circuitry.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114181089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chin-Yiu Chan, Yi‐Ting Lee, Masaki Tanaka, Yiu-Wing Wong, H. Nakanotani, C. Adachi
Organic light-emitting diodes (OLEDs) are a promising light-emitting technology useful for various display applications. Despite great progress in this field, there is an ongoing challenge to realize high-performance blue OLEDs with efficiency, good color purity, and device lifetime. Here, we report pure-blue (CIEx,y color coordinates of [0.13, 0.16]) OLEDs with high-efficiency (external quantum efficiency of 32 % at 1000 cd m–2), narrow-emission (full-width half maximum of 19 nm), and good stability (LT95 of 18 hours at an initial luminance of 1000 cd m–2). The design is based on a two-unit stacked tandem hyperfluorescence (HF)-OLED with an improved singlet-excited energy transfer process from a sky-blue TADF assistant dopant (AD) (HDT-1) to a pure-blue terminal emitter (TE) (v-DABNA). Furthermore, the effect of the dopant concentration of terminal emitter on the device performance of hyperfluorescence OLEDs is studied. The device shows a better color purity when dopant concentration is increased. On the other hand, new hyperfluorescence OLEDs are fabricated, in which v-DABNA is replaced by DABNA-2 and dopant concentration is kept to be 0.5 %. Such device shows a lengthened device stability of LT95 of 26 h at an initial luminance of 1000 cd m-2
有机发光二极管(oled)是一种很有前途的发光技术，可用于各种显示应用。尽管在这一领域取得了巨大的进步，但实现高效、良好的色彩纯度和器件寿命的高性能蓝色oled仍然存在挑战。在这里，我们报道了纯蓝色(CIEx,y色坐标为[0.13,0.16])oled，具有高效率(在1000 cd m-2时外量子效率为32%)，窄发射(全宽度一半最大值为19 nm)和良好的稳定性(在1000 cd m-2的初始亮度下LT95为18小时)。该设计基于双单元堆叠串联高荧光(HF)-OLED，具有改进的单重激发能量转移过程，从天蓝色TADF辅助掺杂剂(AD) (HDT-1)到纯蓝色终端发射器(TE) (v-DABNA)。进一步研究了终端发射极掺杂浓度对高荧光oled器件性能的影响。随着掺杂剂浓度的增加，该装置呈现出较好的色纯度。另一方面，用DABNA-2取代v-DABNA，并保持掺杂浓度为0.5%，制备了新型高荧光oled。该器件在初始亮度为1000 cd m-2时的LT95稳定性为26 h
{"title":"Stable pure-blue hyperfluorescence OLEDs","authors":"Chin-Yiu Chan, Yi‐Ting Lee, Masaki Tanaka, Yiu-Wing Wong, H. Nakanotani, C. Adachi","doi":"10.1117/12.2593884","DOIUrl":"https://doi.org/10.1117/12.2593884","url":null,"abstract":"Organic light-emitting diodes (OLEDs) are a promising light-emitting technology useful for various display applications. Despite great progress in this field, there is an ongoing challenge to realize high-performance blue OLEDs with efficiency, good color purity, and device lifetime. Here, we report pure-blue (CIEx,y color coordinates of [0.13, 0.16]) OLEDs with high-efficiency (external quantum efficiency of 32 % at 1000 cd m–2), narrow-emission (full-width half maximum of 19 nm), and good stability (LT95 of 18 hours at an initial luminance of 1000 cd m–2). The design is based on a two-unit stacked tandem hyperfluorescence (HF)-OLED with an improved singlet-excited energy transfer process from a sky-blue TADF assistant dopant (AD) (HDT-1) to a pure-blue terminal emitter (TE) (v-DABNA). Furthermore, the effect of the dopant concentration of terminal emitter on the device performance of hyperfluorescence OLEDs is studied. The device shows a better color purity when dopant concentration is increased. On the other hand, new hyperfluorescence OLEDs are fabricated, in which v-DABNA is replaced by DABNA-2 and dopant concentration is kept to be 0.5 %. Such device shows a lengthened device stability of LT95 of 26 h at an initial luminance of 1000 cd m-2","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115917618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic–inorganic hybrid perovskites such as methylammonium lead halide (CH3NH3PbI3) have been employed in photoelectronic device applications such as light-emitting diodes, solar cells, field-effect transistors, and photodetectors. Combining ultraviolet photoemission spectroscopy(UPS), X-ray photoemission spectroscopy (XPS), atomic force microscopy(AFM), X-ray diffraction measurements (XRD), and device fabrication and characterization, we performed a systematic investigation on the correlation of energy level alignment, film growth and molecular orientation of a number of interfaces and their modifications in photodetectors based on CH3NH3PbI3 and FA0.4MA0.6PbI3.
{"title":"Interfacial modification for high performance photodetector based on perovskite","authors":"Lin Li, Haipeng Xie, Xiaolian Liu, Dongmei Niu, Jun-liang Yang, Yongli Gao","doi":"10.1117/12.2595233","DOIUrl":"https://doi.org/10.1117/12.2595233","url":null,"abstract":"Organic–inorganic hybrid perovskites such as methylammonium lead halide (CH3NH3PbI3) have been employed in photoelectronic device applications such as light-emitting diodes, solar cells, field-effect transistors, and photodetectors. Combining ultraviolet photoemission spectroscopy(UPS), X-ray photoemission spectroscopy (XPS), atomic force microscopy(AFM), X-ray diffraction measurements (XRD), and device fabrication and characterization, we performed a systematic investigation on the correlation of energy level alignment, film growth and molecular orientation of a number of interfaces and their modifications in photodetectors based on CH3NH3PbI3 and FA0.4MA0.6PbI3.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121698429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multi-material 3D printing has attracted much attention due to its ability to produce functional 3D structures. We have developed several types of multi-material micro stereolithography systems including multi-tank type and single cylinder type. Recently, a multi-material micro stereolithography system based on single-photon polymerization using multiple droplets was also developed. In the multi-material micro stereolithography system, several types of photocurable resins are stored on a palette that is moved by a translation stage. Heterogeneous 3D microstructures are formed by accumulating each layer while exchanging the resins. In this system, two cleaning tanks are installed to prevent contamination of resin. Additionally, to prevent inclusion of air bubbles into the 3D-printed parts, the platform supporting the 3D-printed part was moved in horizontal plane. As a result, air bubbles were successfully pushed out of the fabrication area. Using several types of photocurable resins with different colors, multicolor 3D microstructures such as cubes and lattices were fabricated. By adjusting the number of accumulated layers, the color of the 3D-printed structure can be controlled. These multi-material micro stereolithography systems will be useful for producing functional microdevices including microfluidic elements, micromachines and scaffolds.
{"title":"Multi-material micro stereolithography using multiple droplets of photopolymers for the production of heterogeneous structures","authors":"S. Maruo","doi":"10.1117/12.2595043","DOIUrl":"https://doi.org/10.1117/12.2595043","url":null,"abstract":"Multi-material 3D printing has attracted much attention due to its ability to produce functional 3D structures. We have developed several types of multi-material micro stereolithography systems including multi-tank type and single cylinder type. Recently, a multi-material micro stereolithography system based on single-photon polymerization using multiple droplets was also developed. In the multi-material micro stereolithography system, several types of photocurable resins are stored on a palette that is moved by a translation stage. Heterogeneous 3D microstructures are formed by accumulating each layer while exchanging the resins. In this system, two cleaning tanks are installed to prevent contamination of resin. Additionally, to prevent inclusion of air bubbles into the 3D-printed parts, the platform supporting the 3D-printed part was moved in horizontal plane. As a result, air bubbles were successfully pushed out of the fabrication area. Using several types of photocurable resins with different colors, multicolor 3D microstructures such as cubes and lattices were fabricated. By adjusting the number of accumulated layers, the color of the 3D-printed structure can be controlled. These multi-material micro stereolithography systems will be useful for producing functional microdevices including microfluidic elements, micromachines and scaffolds.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"266 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125722959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Darwin Castillo Malla, Aramis Sánchez, Jandry González, Cristian Chamba, V. Lakshminarayanan
The ultraviolet (UV) index is an international standard measure of the strength of solar ultraviolet radiation on the earth's surface at a specific place and time. Solar radiation with a high UV index can produce damage to the skin and eye (photoaging and photokeratitis). The levels of UV radiation are commonly detected using silicon-based optoelectronic sensors, which can be expensive. Here we propose a way to measure the UV index using natural organic pigments which fluoresce when exposed to UV radiation. In combination with an optical fiber, we have built a prototype sensor based on the pigment of turmeric or "Curcuma Longa". Curcuma longa fluoresces in the range of 500 to 680 nm when exposed to UV radiation. The system uses a filter to isolate the sunlight UV component. The sensor measures the variation in fluorescence intensity using a light dependent resistor to determine radiation levels and correlate it with the UV index. The sensor has been tested in Loja, Ecuador which is located at the equator (UV levels can reach up to 20.0 at the equator). When compared to a standard commercially available sensor (ML8511/LAPIS Semiconductor) this prototype has an error of ± 2.8%. We will describe the optical design and present measurements made with this novel inexpensive sensor.
{"title":"Natural pigment sensor for solar ultraviolet radiation measurement","authors":"Darwin Castillo Malla, Aramis Sánchez, Jandry González, Cristian Chamba, V. Lakshminarayanan","doi":"10.1117/12.2597616","DOIUrl":"https://doi.org/10.1117/12.2597616","url":null,"abstract":"The ultraviolet (UV) index is an international standard measure of the strength of solar ultraviolet radiation on the earth's surface at a specific place and time. Solar radiation with a high UV index can produce damage to the skin and eye (photoaging and photokeratitis). The levels of UV radiation are commonly detected using silicon-based optoelectronic sensors, which can be expensive. Here we propose a way to measure the UV index using natural organic pigments which fluoresce when exposed to UV radiation. In combination with an optical fiber, we have built a prototype sensor based on the pigment of turmeric or \"Curcuma Longa\". Curcuma longa fluoresces in the range of 500 to 680 nm when exposed to UV radiation. The system uses a filter to isolate the sunlight UV component. The sensor measures the variation in fluorescence intensity using a light dependent resistor to determine radiation levels and correlate it with the UV index. The sensor has been tested in Loja, Ecuador which is located at the equator (UV levels can reach up to 20.0 at the equator). When compared to a standard commercially available sensor (ML8511/LAPIS Semiconductor) this prototype has an error of ± 2.8%. We will describe the optical design and present measurements made with this novel inexpensive sensor.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124575608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Presti, Julián Bergier, Jeffry H. Martínez Valdiviezo, M. Bilen, G. Torchia
In recent years, Argentina and countries of the region, have suffered epidemics associated with arboviruses, mainly Dengue and more recently Zika and Chikungunya. On the other hand, since the worldwide pandemic of SARS-CoV-2 (COVID-19), people’s health and the economic support of their countries have been seriously affected. It is necessary to have economic and faster diagnostic tools that allows evaluating samples of patients with symptoms. With this objective, diagnostic systems called point of care have been recently developed. These systems are defined as medical diagnostic testing at or near the point of care (that is, at the time and place of patient care). Specifically, in this work, a bio-photonic device has been developed. This instrument is able to detect certain diseases by means of a luminescence spectral analysis. This method can be conducted for saliva samples. The system consists in the fluorescence signal detection generated by a specific probe of the target viral genome, that coupled to isothermal amplification reaction, allowing the detection of the pathogen in the sample. The device excites the sample to be analyzed with light (led or semiconductor lasers with specific wavelengths) thus it triggers a spontaneous emission of the fluorophore bound to the specific probe. The emitted fluorescence is suitably filtered using interferential filters. These filters limit the spectral regions and allow discriminating the analysis band. Under these conditions, a signal is registered in a built-in detector and, depending on the signal level, define the case as positive or negative. All the analysis is done autonomously inside the developed device through an integrated control system and it is connected to a portable device to show the results wirelessly.
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