Antibiotic residues are regulated in commercially produced milk, with elevated concentrations being harmful. Detection of these antibiotic residues in milk pose a significant challenge for supply chain stakeholders due to the industry standard practice of low-interval off-site laboratory testing. This practice poses risk of non-compliant milk going undetected during on-site milk collection. On-site microfluidic technologies with integrated optical sensors are positioned to mitigate this challenge using increased screening intervals. Droplet-based (digital) microfluidic systems show promise to provide highthroughput screening in dairy applications with integrated fluorescence spectroscopy technologies. However, conventional digital microfluidic systems are subject to biofouling from the protein and fat content within milk. In this work, a biofouling-resistant digital microfluidic platform is introduced. The digital microfluidic platform leverages advancements in parafilm layers, and is demonstrated with actuation of milk and water microdroplets. Electrowetting-based microdroplet actuation is achieved via scalable grid arrays of uniplanar printed surface electrodes in open and closed system configurations. For this array technology, a reconfigurable firmware is developed for user control of automated microdroplet actuation at up to three hundred volts using a graphical computer interface. An exposition of the microdroplet actuation performance is demonstrated and assessed through an optical system for closed-open feedback and positioning of microdroplets. This optical closed-loop allows the actuation velocity of microdroplets to be characterized for polydimethylsiloxane and parafilm dielectric layers, for both water and milk as a function of frequency and voltage. Scalability and automation of the microfluidic platform is discussed, and future integration of fluorescence spectroscopy is investigated.
{"title":"A scalable digital microfluidic platform for automation of onsite testing of dairy samples","authors":"R. Eswar, C. Brodie, C. Collier","doi":"10.1117/12.2594613","DOIUrl":"https://doi.org/10.1117/12.2594613","url":null,"abstract":"Antibiotic residues are regulated in commercially produced milk, with elevated concentrations being harmful. Detection of these antibiotic residues in milk pose a significant challenge for supply chain stakeholders due to the industry standard practice of low-interval off-site laboratory testing. This practice poses risk of non-compliant milk going undetected during on-site milk collection. On-site microfluidic technologies with integrated optical sensors are positioned to mitigate this challenge using increased screening intervals. Droplet-based (digital) microfluidic systems show promise to provide highthroughput screening in dairy applications with integrated fluorescence spectroscopy technologies. However, conventional digital microfluidic systems are subject to biofouling from the protein and fat content within milk. In this work, a biofouling-resistant digital microfluidic platform is introduced. The digital microfluidic platform leverages advancements in parafilm layers, and is demonstrated with actuation of milk and water microdroplets. Electrowetting-based microdroplet actuation is achieved via scalable grid arrays of uniplanar printed surface electrodes in open and closed system configurations. For this array technology, a reconfigurable firmware is developed for user control of automated microdroplet actuation at up to three hundred volts using a graphical computer interface. An exposition of the microdroplet actuation performance is demonstrated and assessed through an optical system for closed-open feedback and positioning of microdroplets. This optical closed-loop allows the actuation velocity of microdroplets to be characterized for polydimethylsiloxane and parafilm dielectric layers, for both water and milk as a function of frequency and voltage. Scalability and automation of the microfluidic platform is discussed, and future integration of fluorescence spectroscopy is investigated.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"134 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114059238","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}
Erkan Aydin, Thomas G. Allen, M. De Bastiani, Lujia Xu, Esma Ugur, A. Ahmed, M. Salvador, E. van Kerschaver, S. De Wolf
Perovskite/silicon tandem solar cells promise power conversion efficiencies (PCE) beyond the thermodynamic limit of single-junction devices. This potential has been unveiled via several champion devices, however, their actual outdoor performance is yet to be investigated. Here, we fabricate 25 %-efficient two-terminal (2T) monolithic perovskite/silicon tandem solar cells and test them outdoors to reveal the characteristics of these devices specifically in hot and sunny climates, which are the ideal locations to operate such efficient photovoltaic devices. In this article, we summarize our observation on the perovskite/silicon tandem solar cells under actual operational conditions and discuss the lessons we take from our interpretations.
{"title":"Lessons learned from the first outdoor test of perovskite/silicon tandem solar cells","authors":"Erkan Aydin, Thomas G. Allen, M. De Bastiani, Lujia Xu, Esma Ugur, A. Ahmed, M. Salvador, E. van Kerschaver, S. De Wolf","doi":"10.1117/12.2595032","DOIUrl":"https://doi.org/10.1117/12.2595032","url":null,"abstract":"Perovskite/silicon tandem solar cells promise power conversion efficiencies (PCE) beyond the thermodynamic limit of single-junction devices. This potential has been unveiled via several champion devices, however, their actual outdoor performance is yet to be investigated. Here, we fabricate 25 %-efficient two-terminal (2T) monolithic perovskite/silicon tandem solar cells and test them outdoors to reveal the characteristics of these devices specifically in hot and sunny climates, which are the ideal locations to operate such efficient photovoltaic devices. In this article, we summarize our observation on the perovskite/silicon tandem solar cells under actual operational conditions and discuss the lessons we take from our interpretations.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"66 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":"129547979","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}
An approach to enhance the lifetime of a phosphorescent organic light-emitting diode (PHOLED) with a solutionprocessed hole-transport layer (HTL) by employing energy transfer from an exciplex to a phosphorescent emitter is presented. Using the structure of solution-coated Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-secbutylphenyl) diphenylamine)] (TFB) as a HTL and vacuum-deposited 4,4′-Bis(carbazol-9-yl)biphenyl (CBP) as a host provides a suitable situation for the formation of exciplex between CBP and TFB because energy gap between the LUMO level of CBP and the HOMO level of TFB becomes much smaller than the HOMO-LUMO gap of CBP or TFB. As the PHOLED emission is solely from the phosphorescence, the intermediate exciplex state rapidly transfers its energy to the dopant triplet. Since singlet-excited state of exciplex requires much lower energy than singlet-excited state of the host, driving voltage for PHOLEDs using exciplex–triplet energy transfer (ExTET) is lower than conventional, leading to longer device lifetime. The results show that the electroluminescence half-life (LT50) of fabricated device with the structure of HTL TFB and host CBP in which exciplex can form between CBP and TFB is about 5785 h (for an initial luminance of 1000 cd m−2). On the other hand, in the other fabricated devices with the same structure and just mixing TFB with other materials with deeper HOMO level, where the ability to form exciplex between TFB and CBP is suppressed, the device lifetime is significantly shorter. To the best of our knowledge, it is the first time that ExTET is obtained in a hybrid structure involving solution-coated and vacuum-deposited layers.
提出了一种利用从外加复合物到磷光发射器的能量转移来提高具有溶液处理空穴传输层的磷光有机发光二极管(PHOLED)寿命的方法。采用溶液包覆的聚[(9,9-二辛基芴基-2,7-二基)-co-(4,4 ' -(N-(4-叔丁基苯基)二苯胺](TFB)结构作为HTL，真空沉积4,4 ' -双(卡巴唑-9-基)联苯(CBP)作为宿主，为CBP与TFB之间形成异构体提供了合适的条件，因为CBP的LUMO能级与TFB的HOMO能级之间的能隙比CBP或TFB的HOMO-LUMO能级之间的能隙要小得多。由于PHOLED的发射完全来自磷光，中间的外杂态迅速将其能量转移到掺杂三重态。由于双工态的单线激发态比主机的单线激发态所需的能量要低得多，因此使用双工态-三重态能量转移(ExTET)的二极管的驱动电压比传统的低，从而延长了器件的使用寿命。结果表明，在初始亮度为1000 cd m−2的条件下，HTL TFB和宿主CBP结构的电致发光器件的电致发光半衰期(LT50)约为5785 h。另一方面，在相同结构的其他制备器件中，仅将TFB与其他HOMO能级较深的材料混合，抑制了TFB与CBP之间形成外杂的能力，器件寿命明显缩短。据我们所知，这是第一次在溶液涂层和真空沉积层的混合结构中获得ExTET。
{"title":"Improvement in the stability of phosphorescent OLED with solution-coated hole-transport layer via exciplex–triplet energy transfer","authors":"F. Samaeifar, H. Aziz","doi":"10.1117/12.2597360","DOIUrl":"https://doi.org/10.1117/12.2597360","url":null,"abstract":"An approach to enhance the lifetime of a phosphorescent organic light-emitting diode (PHOLED) with a solutionprocessed hole-transport layer (HTL) by employing energy transfer from an exciplex to a phosphorescent emitter is presented. Using the structure of solution-coated Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-secbutylphenyl) diphenylamine)] (TFB) as a HTL and vacuum-deposited 4,4′-Bis(carbazol-9-yl)biphenyl (CBP) as a host provides a suitable situation for the formation of exciplex between CBP and TFB because energy gap between the LUMO level of CBP and the HOMO level of TFB becomes much smaller than the HOMO-LUMO gap of CBP or TFB. As the PHOLED emission is solely from the phosphorescence, the intermediate exciplex state rapidly transfers its energy to the dopant triplet. Since singlet-excited state of exciplex requires much lower energy than singlet-excited state of the host, driving voltage for PHOLEDs using exciplex–triplet energy transfer (ExTET) is lower than conventional, leading to longer device lifetime. The results show that the electroluminescence half-life (LT50) of fabricated device with the structure of HTL TFB and host CBP in which exciplex can form between CBP and TFB is about 5785 h (for an initial luminance of 1000 cd m−2). On the other hand, in the other fabricated devices with the same structure and just mixing TFB with other materials with deeper HOMO level, where the ability to form exciplex between TFB and CBP is suppressed, the device lifetime is significantly shorter. To the best of our knowledge, it is the first time that ExTET is obtained in a hybrid structure involving solution-coated and vacuum-deposited layers.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"20 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":"126896249","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}
We report materials and device designs of solution-processable organic photodiodes (OPDs) for visible or near-infrared (NIR) light detection compatible with CMOS image sensors (CIS), a large market for photodiodes. OPDs for CIS need to be reliably processable on silicon wafers with conventional methods such as spin coating, to have extremely low dark current even at a couple of negative voltages to utilize high gain read-out circuits, and to be stable under 150–250°C heating to endure module packaging. Those requirements have not been taken into an account for organic photovoltaics (OPVs) development, which assumed large area printing at low processing temperature (<150°C). We selected a conventional structure (p-i-n) with a polymeric hole transport layer (HTL) which we originally made for organic light-emitting diodes (OLEDs). The HTL is free from acids and dopants, contributing to excellent device stability. For visible OPDs, we applied a donor/acceptor blend originally made for OPVs, and obtained an external quantum yield (EQE) of ~85% at 450–700 nm with a dark current of ~10−7 mA/cm2. For NIR OPDs targeting 940 nm, we newly developed NIR absorbing non-fullerene acceptors (NFAs) having a sharp absorption peak at the wavelength to realize high EQE (~80%) and low thermal carriers at dark (~10−5 mA/cm2). Both type of OPDs retained 70–100% of their original EQEs after thermal annealing at <150°C for two hours. In the presentation video, we will show NIR images obtained from the imaging arrays.
{"title":"Solution-processable organic photodiodes with high detectivity and thermal stability designed for visible or near-infrared CMOS image sensors","authors":"Hidneori Nakayama, Kazuhiro Nakabayashi, R. Hata, Kazuhiro Mouri, Shigeru Nakane, Izuru Takei","doi":"10.1117/12.2593410","DOIUrl":"https://doi.org/10.1117/12.2593410","url":null,"abstract":"We report materials and device designs of solution-processable organic photodiodes (OPDs) for visible or near-infrared (NIR) light detection compatible with CMOS image sensors (CIS), a large market for photodiodes. OPDs for CIS need to be reliably processable on silicon wafers with conventional methods such as spin coating, to have extremely low dark current even at a couple of negative voltages to utilize high gain read-out circuits, and to be stable under 150–250°C heating to endure module packaging. Those requirements have not been taken into an account for organic photovoltaics (OPVs) development, which assumed large area printing at low processing temperature (<150°C). We selected a conventional structure (p-i-n) with a polymeric hole transport layer (HTL) which we originally made for organic light-emitting diodes (OLEDs). The HTL is free from acids and dopants, contributing to excellent device stability. For visible OPDs, we applied a donor/acceptor blend originally made for OPVs, and obtained an external quantum yield (EQE) of ~85% at 450–700 nm with a dark current of ~10−7 mA/cm2. For NIR OPDs targeting 940 nm, we newly developed NIR absorbing non-fullerene acceptors (NFAs) having a sharp absorption peak at the wavelength to realize high EQE (~80%) and low thermal carriers at dark (~10−5 mA/cm2). Both type of OPDs retained 70–100% of their original EQEs after thermal annealing at <150°C for two hours. In the presentation video, we will show NIR images obtained from the imaging arrays.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"11809 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":"130001674","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}
The solvent-robustness and temporal stability of polyethylenimine (PEI) as an electron extraction layer (EEL) in inverted organic solar cells (OSCs) were studied. For that purpose, a PEI EEL is utilized in inverted OSCs with the archetypal Poly (3-hexylthiophene) (P3HT): [6,6]-Phenyl C61 butyric acid methyl ester (PC60BM) donor:acceptor system. Results show that soaking the PEI film in solvents (1-propanol and/or toluene) does not significantly impact OSC performance or photostability. As verified by X-ray photoelectron spectroscopy (XPS) measurements, the N atoms in PEI interact with indium-tin-oxide (ITO), causing PEI to strongly adhere to the surface of ITO so that potential processing solvents do not dissolve it. Shifts in N bands in the case of PEI on ITO compared to the PEI on glass confirm the presence of a strong physical interaction. In addition, comparing OSCs with fresh PEI and N2-stored PEI demonstrates that the PEI film is very stable over time, and a time gap between PEI deposition and subsequent fabrication processes does not affect OSC performance and photostability. We highlight that the utilization of PEI as a stable and robust EEL facilitates bridging between laboratory discoveries of OSCs with their practical demonstration and gives us considerable latitude in tackling the stringent requirements of OSC manufacturing.
{"title":"The potential benefits of polyethylenimine as an electron extraction layer for facilitating the manufacturing of inverted organic solar cells","authors":"Mozhgan Sadeghianlemraski, H. Aziz","doi":"10.1117/12.2597312","DOIUrl":"https://doi.org/10.1117/12.2597312","url":null,"abstract":"The solvent-robustness and temporal stability of polyethylenimine (PEI) as an electron extraction layer (EEL) in inverted organic solar cells (OSCs) were studied. For that purpose, a PEI EEL is utilized in inverted OSCs with the archetypal Poly (3-hexylthiophene) (P3HT): [6,6]-Phenyl C61 butyric acid methyl ester (PC60BM) donor:acceptor system. Results show that soaking the PEI film in solvents (1-propanol and/or toluene) does not significantly impact OSC performance or photostability. As verified by X-ray photoelectron spectroscopy (XPS) measurements, the N atoms in PEI interact with indium-tin-oxide (ITO), causing PEI to strongly adhere to the surface of ITO so that potential processing solvents do not dissolve it. Shifts in N bands in the case of PEI on ITO compared to the PEI on glass confirm the presence of a strong physical interaction. In addition, comparing OSCs with fresh PEI and N2-stored PEI demonstrates that the PEI film is very stable over time, and a time gap between PEI deposition and subsequent fabrication processes does not affect OSC performance and photostability. We highlight that the utilization of PEI as a stable and robust EEL facilitates bridging between laboratory discoveries of OSCs with their practical demonstration and gives us considerable latitude in tackling the stringent requirements of OSC manufacturing.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"20 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":"130085116","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}
B. Guo, Shiyu Xing, Yaxin Wang, Runchen Lai, Baodan Zhao, D. Di
Perovskite light-emitting diodes (PeLEDs) have shown great potential for next-generation display and solid-state lighting applications. In the related field of perovskite solar cells, preventing the conversion of the photovoltaically active black phase (α-phase) into the less desirable yellow phase (δ-phase) is of critical importance for achieving efficient and stable solar cells based on formamidinium lead iodide (FAPbI3) perovskite. Similar issues related to phase stability are expected to occur in PeLEDs, leading to reduced operational stability and the formation of additional electronic traps. In this work, we introduce an additive, sulfobetaine 10 (SFB-10), into the FAPbI3 perovskite for α-phase stabilization. The SFB-10 incorporated perovskite films show enhanced crystallinity, reduced defect density and improved α-phase stability, leading to high-performance PeLEDs with external quantum efficiencies exceeding 16%, and T90 (the time for radiance to decrease to 90% of its initial value) of over 1000 s at 200 mA cm-2 in air, offering a comparable performance to some of the most stable PeLEDs reported to date. This work may contribute to the development of stable perovskite light-emitting diodes.
钙钛矿发光二极管(PeLEDs)在下一代显示和固态照明应用中显示出巨大的潜力。在钙钛矿太阳能电池的相关领域，防止光伏活性黑色相(α-相)转化为不理想的黄色相(δ-相)是实现高效稳定的钙钛矿钙钛矿太阳能电池的关键。与相位稳定性相关的类似问题预计也会出现在ped中，导致操作稳定性降低和形成额外的电子陷阱。在这项工作中，我们在FAPbI3钙钛矿中引入了一种添加剂，磺胺甜菜碱10 (SFB-10)，用于α-相稳定。SFB-10掺杂的钙钛矿薄膜结晶度增强，缺陷密度降低，α-相稳定性提高，导致高性能pled的外部量子效率超过16%，在空气中200 mA cm-2下T90(亮度降低到初始值的90%的时间)超过1000 s，提供了迄今为止报道的一些最稳定的pled的性能。这项工作可能有助于开发稳定的钙钛矿发光二极管。
{"title":"Phase stabilization for high-performance perovskite light-emitting diodes","authors":"B. Guo, Shiyu Xing, Yaxin Wang, Runchen Lai, Baodan Zhao, D. Di","doi":"10.1117/12.2595197","DOIUrl":"https://doi.org/10.1117/12.2595197","url":null,"abstract":"Perovskite light-emitting diodes (PeLEDs) have shown great potential for next-generation display and solid-state lighting applications. In the related field of perovskite solar cells, preventing the conversion of the photovoltaically active black phase (α-phase) into the less desirable yellow phase (δ-phase) is of critical importance for achieving efficient and stable solar cells based on formamidinium lead iodide (FAPbI3) perovskite. Similar issues related to phase stability are expected to occur in PeLEDs, leading to reduced operational stability and the formation of additional electronic traps. In this work, we introduce an additive, sulfobetaine 10 (SFB-10), into the FAPbI3 perovskite for α-phase stabilization. The SFB-10 incorporated perovskite films show enhanced crystallinity, reduced defect density and improved α-phase stability, leading to high-performance PeLEDs with external quantum efficiencies exceeding 16%, and T90 (the time for radiance to decrease to 90% of its initial value) of over 1000 s at 200 mA cm-2 in air, offering a comparable performance to some of the most stable PeLEDs reported to date. This work may contribute to the development of stable perovskite light-emitting diodes.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"2 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":"125159984","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}
H. Abroshan, Anand Chandrasekaran, P. Winget, Yuling An, Shaun H. Kwak, C. Brown, M. Halls
To date, the development of organic light-emitting diode (OLED) materials has been primarily based on a combination of chemical intuition and trial-and-error experimentation. The approach is often expensive and time-consuming, let alone in most instances fails to offer new materials leading to higher efficiencies. Data-driven approaches have emerged as a powerful tool to accelerate the design and discovery of novel materials with multifunctional properties for next generation OLED technologies. Virtual high-throughput methods assisted by machine learning (ML) enable a broad screening of chemical space to predict material properties and suggest new candidates for OLEDs. In order to build reliable predictive ML models for OLED materials, it is required to create and manage a high volume of data which not only maintain high accuracy but also properly assess the complexity of materials chemistry in the OLED space. Active learning (AL) is among several strategies developed to face the challenge in both materials science and life science applications, where the data management in large-scale becomes a main bottleneck. Here, we present a workflow that efficiently combines AL with atomic-scale simulations to reliably predict optoelectronic properties of OLED materials. This study provides a robust and validated framework to account for multiple parameters that simultaneously influence OLED performance. Results of this work pave the way for a fundamental understanding of optoelectronic performance of emergent layers from a molecular perspective, and further screen candidate materials with superior efficiencies before laborious simulations, synthesis, and device fabrication.
{"title":"Accelerated design and optimization of novel OLED materials via active learning","authors":"H. Abroshan, Anand Chandrasekaran, P. Winget, Yuling An, Shaun H. Kwak, C. Brown, M. Halls","doi":"10.1117/12.2598140","DOIUrl":"https://doi.org/10.1117/12.2598140","url":null,"abstract":"To date, the development of organic light-emitting diode (OLED) materials has been primarily based on a combination of chemical intuition and trial-and-error experimentation. The approach is often expensive and time-consuming, let alone in most instances fails to offer new materials leading to higher efficiencies. Data-driven approaches have emerged as a powerful tool to accelerate the design and discovery of novel materials with multifunctional properties for next generation OLED technologies. Virtual high-throughput methods assisted by machine learning (ML) enable a broad screening of chemical space to predict material properties and suggest new candidates for OLEDs. In order to build reliable predictive ML models for OLED materials, it is required to create and manage a high volume of data which not only maintain high accuracy but also properly assess the complexity of materials chemistry in the OLED space. Active learning (AL) is among several strategies developed to face the challenge in both materials science and life science applications, where the data management in large-scale becomes a main bottleneck. Here, we present a workflow that efficiently combines AL with atomic-scale simulations to reliably predict optoelectronic properties of OLED materials. This study provides a robust and validated framework to account for multiple parameters that simultaneously influence OLED performance. Results of this work pave the way for a fundamental understanding of optoelectronic performance of emergent layers from a molecular perspective, and further screen candidate materials with superior efficiencies before laborious simulations, synthesis, and device fabrication.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"11808 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":"130716575","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}
Laser beams which carry spin and orbital angular momentum are desired in many applications. They are usually created by manipulating the laser output or by inserting optical components in the laser cavity. Due to their high susceptibility to external fields and birefringent nature, control over the emitted light could be achieved by inserting liquid crystals into the laser cavity. In this work we numerically study lasing in selected nematic liquid crystal director profiles. We use custom written FDFD code to calculate emergent electromagnetic eigenmodes, and show how they are affected by the nematic director field. Control over lasing is of a particular interest with the aim to path the way towards the creation of general arbitrary shaped laser beams.
{"title":"Numerical modeling of optical modes in nematic droplets","authors":"Urban Mur, M. Ravnik","doi":"10.1117/12.2569382","DOIUrl":"https://doi.org/10.1117/12.2569382","url":null,"abstract":"Laser beams which carry spin and orbital angular momentum are desired in many applications. They are usually created by manipulating the laser output or by inserting optical components in the laser cavity. Due to their high susceptibility to external fields and birefringent nature, control over the emitted light could be achieved by inserting liquid crystals into the laser cavity. In this work we numerically study lasing in selected nematic liquid crystal director profiles. We use custom written FDFD code to calculate emergent electromagnetic eigenmodes, and show how they are affected by the nematic director field. Control over lasing is of a particular interest with the aim to path the way towards the creation of general arbitrary shaped laser beams.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"742 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133402430","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}
Ikram Anefnaf, S. Aazou, G. Schmerber, A. Dinia, Z. Sekkat
The inverted organic solar cell devices (iOSCs) were fabricated with different weight ratios 1:0.6, 1:0.8, and 1:1 of P3HT and PCBM, respectively. The photo-physical properties of these devices with varying weight ratios are investigated. We find that the absorption spectra revealed a decrease in the intensities with increasing the fullerene ratio and the peaks were blue shifted. Thin films morphology is evaluated by atomic force microscopy (AFM). The PL quenching suggests that the transfer of photo-induced electrons from P3HT to PCBM increases hugely with an increase in the amount of PCBM. Raman spectroscopy for devices shows a strong reduction in the crystallinity by increasing the ratio of fullerene within the blend. The J-V measurements for all devices were performed under the illumination of simulated AM 1.5 sunlight at 100 mW/cm2. External quantum efficiency (EQE) and Internal quantum efficiency (IQE) measurements are also performed for the best device. The best performance was recorded for the device with 1:1 weight ratio of P3HT and PCBM give Power Conversion Efficiency (PCE) of 3.67%, in contrast to 3.36% for (1:0.8) and 2.51% for 1:0.6 devices.
{"title":"Study the effect of fullerene derivatives ratio on P3HT-based inverted organic solar cells","authors":"Ikram Anefnaf, S. Aazou, G. Schmerber, A. Dinia, Z. Sekkat","doi":"10.1117/12.2568790","DOIUrl":"https://doi.org/10.1117/12.2568790","url":null,"abstract":"The inverted organic solar cell devices (iOSCs) were fabricated with different weight ratios 1:0.6, 1:0.8, and 1:1 of P3HT and PCBM, respectively. The photo-physical properties of these devices with varying weight ratios are investigated. We find that the absorption spectra revealed a decrease in the intensities with increasing the fullerene ratio and the peaks were blue shifted. Thin films morphology is evaluated by atomic force microscopy (AFM). The PL quenching suggests that the transfer of photo-induced electrons from P3HT to PCBM increases hugely with an increase in the amount of PCBM. Raman spectroscopy for devices shows a strong reduction in the crystallinity by increasing the ratio of fullerene within the blend. The J-V measurements for all devices were performed under the illumination of simulated AM 1.5 sunlight at 100 mW/cm2. External quantum efficiency (EQE) and Internal quantum efficiency (IQE) measurements are also performed for the best device. The best performance was recorded for the device with 1:1 weight ratio of P3HT and PCBM give Power Conversion Efficiency (PCE) of 3.67%, in contrast to 3.36% for (1:0.8) and 2.51% for 1:0.6 devices.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132137657","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}
Md. Asiqur Rahman, T. Truong, J. H. Park, Hakam Agha, D. Suh, G. Scalia
Free-standing veils of parallel carbon nanotube (CNTs) wires can be easily integrated in devices as transparent and conductive layers and they are particularly interesting for liquid crystals since they can act also as aligning layers. We have realized cells for liquid crystals using aligned carbon nanotube wires in sheets drawn from spinnable forests and obtained light modulation by switching the LC. The 5CB and E7 nematic liquid crystal align planarly and the unidirectional alignment direction is determined by the CNT orientation within the sheets and by applying the voltage directly to the CNTs we obtained the electro-optic switching with the LC. The CNT sheets prove to be efficient multifunctional layers for new LC displays, perfectly compatible with flexible substrates due to their mechanical characteristics as it will be described here.
{"title":"Integrated carbon nanotubes for novel liquid crystal displays","authors":"Md. Asiqur Rahman, T. Truong, J. H. Park, Hakam Agha, D. Suh, G. Scalia","doi":"10.1117/12.2569361","DOIUrl":"https://doi.org/10.1117/12.2569361","url":null,"abstract":"Free-standing veils of parallel carbon nanotube (CNTs) wires can be easily integrated in devices as transparent and conductive layers and they are particularly interesting for liquid crystals since they can act also as aligning layers. We have realized cells for liquid crystals using aligned carbon nanotube wires in sheets drawn from spinnable forests and obtained light modulation by switching the LC. The 5CB and E7 nematic liquid crystal align planarly and the unidirectional alignment direction is determined by the CNT orientation within the sheets and by applying the voltage directly to the CNTs we obtained the electro-optic switching with the LC. The CNT sheets prove to be efficient multifunctional layers for new LC displays, perfectly compatible with flexible substrates due to their mechanical characteristics as it will be described here.","PeriodicalId":145218,"journal":{"name":"Organic Photonics + Electronics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121283340","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}
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