Journal of Information Display最新文献

{"title":"New europium complexes and their use in red light-emitting diodes and vapoluminescent sensors","authors":"R. Devi, Rajamouli Boddula, Kasturi Singh, Satendra Kumar, S. Vaidyanathan","doi":"10.1080/15980316.2021.1879960","DOIUrl":"https://doi.org/10.1080/15980316.2021.1879960","url":null,"abstract":"Three novel trivalent europium [Eu(III)] complexes – Eu(DBM)3Phen-Ph-Ph, Eu(DBM)3Phen-mCF3-Ph, and Eu(DBM)3Phen-pCF3-Ph – were designed, synthesized, and characterized using various spectroscopic methods. Then their photophysical characteristics were investigated. The Eu complexes in the solid phase showed a pure red emission (due to the electric dipole transitions of the Eu3+ ion). In a solution, they had multiple emissions due to their ligand contribution. The solvatochromism studies revealed that the Eu(III) complexes in the methanol and DMSO solutions had both metal ion and ligand emissions with similar intensities, which yielded a white emission. Of all the Eu(III) complexes, Eu(DBM)3Phen-mCF3-Ph showed the best quantum yield. In addition, the fluorinated mCF3 ligand had an unusually high lifetime value. Its remarkable linear decrease in luminescence intensity with increasing temperature opens a new window for its use as a sensitive temperature sensor at the 30–80°C range. The CIE color coordinates of the fabricated red LEDs (InGaN) are very close to the standard NTSC CIE color coordinates for bright red emissions, and the color purity as well as the LER values of the fabricated red LEDs are also very good. The Eu(III) complexes exhibited on-off photoluminescence switching via the vapoluminescent process and responded best to the acid-base (HCl-NH3) vapors. All these features suggest that the synthesized Eu(III) complexes are efficient candidates for red-emitting LEDs and vapoluminescent sensors. Organic chromophores, which are phenanthro-imidazole ligands based on fluorinated moieties coordinated with Eu(III) metal ions, very efficiently facilitate energy transfer from the ligand to the Eu(III) ion. The CIE color coordinates of the complexes showed a bright pure red emission, with x = 0.66 and y = 0.33 (612 nm). The fabricated light-emitting diode (LED) showed superior color quality and the complexes showed on-off-on luminescence behavior after exposure to the acid-base vapors.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"137 - 151"},"PeriodicalIF":3.7,"publicationDate":"2021-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2021.1879960","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43468942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technical status of top-emission organic light-emitting diodes","authors":"Seong Keun Kim, Raju Lampande, J. Kwon","doi":"10.1080/15980316.2021.1876173","DOIUrl":"https://doi.org/10.1080/15980316.2021.1876173","url":null,"abstract":"Top-emission organic light-emitting diodes (TEOLEDs) that contain semi-transparent metal top cathodes and highly reflective anodes have been actively researched for display applications due to their many advantages such as their high aperture ratio, good color purity, and high efficiency. In this research, the technical design of TEOLEDs used in organic light-emitting diode (OLED) displays is reviewed, covering the optical theory with the microcavity effect, optical losses, and the importance of the Purcell effect in the optical calculation. The key methodologies for addressing the high efficiency and low driving voltage of TEOLEDs are also discussed.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"115 - 126"},"PeriodicalIF":3.7,"publicationDate":"2021-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2021.1876173","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43548133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A more reliable defect detection and performance improvement method for panel inspection based on artificial intelligence","authors":"Eui-Young Jeong, Jaewon Kim, Wonhyouk Jang, Hyun-Chang Lim, Hanaul Noh, Jongmyong Choi","doi":"10.1080/15980316.2021.1876174","DOIUrl":"https://doi.org/10.1080/15980316.2021.1876174","url":null,"abstract":"This paper presents a practical approach to automatic inspection of display panels based on deep neural networks. The approach accurately detects appearance defects on display panels in various sizes and shapes within a short computation time. We propose a novel reliable detection network using the multi-channel parameter reduction method, which preserves high-resolution features of defects at sub-sampling steps of convolutional operations. Our proposed network consists of two sub-networks with different functions: pixel-wise segmentation of defect regions and distinction of real defects from fake defects. Compared with conventional deep learning networks, the proposed network achieved a more accurate detection rate, i.e. an F1-score of 81%, for real defect images acquired from an actual display manufacturing process. In addition, we propose a conditionally paired generative network that generates synthetic images of scarce defects under four different lighting conditions. The proposed networks improved the detection accuracy and can be applied to automatic inspection processes in display manufacturing factories in place of human inspection.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"127 - 136"},"PeriodicalIF":3.7,"publicationDate":"2021-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2021.1876174","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42731530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Passivation layer effect on the positive bias temperature instability of molybdenum disulfide thin film transistors","authors":"Woonggi Hong, D. Oh, Sung‐Yool Choi","doi":"10.1080/15980316.2020.1776407","DOIUrl":"https://doi.org/10.1080/15980316.2020.1776407","url":null,"abstract":"As two-dimensional (2D) materials have a large surface to volume ratio, the stability of thin film transistors (TFTs) is likely to be lowered with air exposure. Therefore, we study the positive bias temperature instability (PBTI) of chemical vapor deposition (CVD) grown molybdenum disulfide (MoS2) TFTs before and after deposition of a passivation layer. The results of the PBTI study demonstrate that the fabricated devices adjust to the stretched-exponential model, which shows a threshold voltage shift attributed to the charge trapping mechanism. However, by depositing the passivation layer (Al2O3) that physically blocks the charge transfer process with O2 and H2O adsorbed to the surface of the MoS2 channel, the threshold voltage shifted reduces from 10 V to 7.4 V under stress condition. The quantitative value of tau (τ), one of the fitting parameters of the stretched-exponential model, also decreases from 6453 s to 5153 s, resulting in improved device stability.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"13 - 19"},"PeriodicalIF":3.7,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2020.1776407","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45551485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of a P-doped hole transport and charge generation layer on single and two-tandem blue top-emitting organic light-emitting diodes","authors":"Jaeyoung Park, Jae-Hyun Lee, Jang-Sik Lee, Hyunsu Cho","doi":"10.1080/15980316.2020.1863273","DOIUrl":"https://doi.org/10.1080/15980316.2020.1863273","url":null,"abstract":"The transmittance of the p-doped hole transporting layer (p-HTL) and the charge generation layer (p-CGL) corresponding to the photoluminescence (PL) of blue dopants in an emitting layer decreases as the ratio of the p-dopant increases due to the absorption of the p-dopant. However, there was little difference in the luminous efficiency of blue top-emitting organic light-emitting diodes using p-HTL or p-CGL at a maximum doping ratio of 20%. p-HTL for a single structure required a 5% doping ratio to ensure sufficient electrical characteristics, but p-CGL for the two-stack tandem structure required more than a 10% doping ratio. The optical simulation showed that the device was affected by the specific absorbance of the p-dopant depending on the doping ratio and thickness. Although there was no significant difference in efficiency depending on the doping ratio at a thickness of 10 nm, the reduction rate of the external quantum efficiency increased from over 20 nm due to the doping ratio.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"107 - 113"},"PeriodicalIF":3.7,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2020.1863273","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45674705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical analysis of the dual-microcavity effect in a red light-emitting organic device","authors":"A. Mikami","doi":"10.1080/15980316.2020.1848934","DOIUrl":"https://doi.org/10.1080/15980316.2020.1848934","url":null,"abstract":"ABSTRACT In this study, the effect of a dual microcavity on the luminescent characteristics and light extraction efficiency of organic red light-emitting devices with a multi-cathode structure was investigated. It was clarified that surface plasmon loss on a metal cathode was reduced to about one-fifth and can be efficiently extracted from the outside with the help of the dual-microcavity effect. About half of the radiant energy in dipole emission was successfully utilized as external and substrate modes. The luminous efficiency increased by about 1.52 times, and a narrow-band emission spectrum was observed with a forward directional red emission. The relationship between the luminescence characteristics and the dual-microcavity effect will be discussed from the viewpoint of the optical design of multi-stacked thin film devices.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"99 - 106"},"PeriodicalIF":3.7,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2020.1848934","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43010086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dictionary-Based interpolation technique for text quality enhancement","authors":"Sung In Cho, Suk-ju Kang","doi":"10.1080/15980316.2020.1843556","DOIUrl":"https://doi.org/10.1080/15980316.2020.1843556","url":null,"abstract":"This paper presents a new dictionary-based interpolation technique to improve text quality when the resolution of an image is increased, so that the text can be displayed on a high-resolution display device. The proposed algorithm analyzes an image and extracts the shape of the text from the image. Further, it encodes and decodes the pattern of the text, and enhances the legibility of the text using a pre-trained code dictionary. Therefore, the proposed method improves text quality in terms of sharpness. In the experiments, the proposed algorithm outperformed benchmark methods for all test images. Specifically, the proposed method reduced the blur index by up to 0.112.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"83 - 89"},"PeriodicalIF":3.7,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2020.1843556","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43539816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of the bulky blocking unit of the fluorescent emitter in efficient green hyper-fluorescent organic light-emitting diodes","authors":"W. J. Chung, Jun Yeob Lee","doi":"10.1080/15980316.2020.1846089","DOIUrl":"https://doi.org/10.1080/15980316.2020.1846089","url":null,"abstract":"The efficiency loss process of hyper-fluorescent organic light-emitting diodes (OLEDs) was analyzed with different fluorescent emitters. Two blocking units of tert-butyl and 2-phenylpropan-2-yl in fluorescent emitters suppressed the Dexter energy transfer from the host and thermally activated delayed fluorescent (TADF) sensitizer to the fluorescent emitter and concentration quenching caused by intermolecular interaction. The performance of the green hyper-fluorescent OLEDs showed that the device of the fluorescent emitter with the 2-phenylpropan-2-yl unit achieved a high external quantum efficiency of 18.1% with a low efficiency roll-off, compared to the device of the fluorescent emitter with the tert-butyl unit. This study demonstrated the usefulness of the 2-phenylpropan-2-yl blocking unit of the fluorescent emitter for hyper-fluorescent OLEDs, and exhibited the directionality of the development of hyper-fluorescent OLEDs.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"49 - 54"},"PeriodicalIF":3.7,"publicationDate":"2020-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2020.1846089","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46558108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel Sm3+-activated Li3BaSrLn3(MO4)8 [Ln = La, Gd, and Y; M = Mo and W] deep red-emitting phosphors for plant cultivation and white LEDs","authors":"Marikumar Rajendran, Kasturi Singh, S. Vaidyanathan","doi":"10.1080/15980316.2020.1831630","DOIUrl":"https://doi.org/10.1080/15980316.2020.1831630","url":null,"abstract":"Deep red phosphor-based LEDs play a crucial role in plant growth applications, where the LED emission covers the phytochrome (Pr) absorption. In this context, a series of Sm3+-activated Li3BaSrLn3(MO4)8:Sm3+ [Ln = La Gd and Y; M = Mo and W] deep red phosphors were synthesized using the solid-state method. The outcome of the PXRD patterns suggests that the synthesized phosphors were crystallized in a monoclinic structure with the space group C2/c. SEM analysis was executed to study the morphology of the phosphors, and an FT-IR study was performed to study the stretching frequency of the MO/W-O bond in the (Mo/W)O4 groups. All the Sm3+-activated phosphors showed intense emission at 646 nm due to their 4G5/2→6H9/2 transition and exhibited excellent thermal stability (> 72% at 423K). The selected phosphors showed internal quantum efficiency at around 30%. The pc-LEDs were fabricated with the combination of near-UV LED and the synthesized deep-red phosphors. Besides, the emission spectrum of the fabricated LED was compared with the phytochrome Pr absorption spectrum for de plant growth application. These results suggest that the synthesized phosphor can be useful in the white LED fabrication to improve the CRI and can also be beneficial in the plant growth field.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"63 - 81"},"PeriodicalIF":3.7,"publicationDate":"2020-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2020.1831630","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43843609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flexible distributed Bragg reflectors as optical outcouplers for OLEDs based on a polymeric anode","authors":"C. T. Prontera, M. Pugliese, R. Giannuzzi, S. Carallo, M. Esposito, G. Gigli, V. Maiorano","doi":"10.1080/15980316.2020.1825537","DOIUrl":"https://doi.org/10.1080/15980316.2020.1825537","url":null,"abstract":"Top-emitting OLEDs (TOLEDs) represent a promising technology for the development of next-generation flexible and rollable displays, thanks to their improved light outcoupling and their compatibility with opaque substrates. Metal thin films are the most used electrodes for the manufacturing of TOLEDs, but they show poor resistance to mechanical deformation, which compromises the long-term durability of flexible devices. This paper reports the exploitation of a dielectric mirror (DBR) based on seven pairs of TiO2 and SiO2 combined with a polymeric electrode as an alternative to the bottom metal electrode in flexible TOLEDs. The DBR showed a maximum reflectivity of 99.9% at about 550 nm, and a stop-band width of about 200 nm. The reflectivity remained unchanged after bending and treatment with water and solvents. Green TOLED devices were fabricated on top of DBRs, and demonstrated good stability in terms of electro-optical and colorimetric characteristics, according to varying viewing angles. These results demonstrate that the combination of the flexible DBR with the polymeric anode is an interesting strategy for improving the durability of flexible TOLEDs for display applications, implemented on different kinds of free-standing ultra-thin substrates.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":"22 1","pages":"39 - 47"},"PeriodicalIF":3.7,"publicationDate":"2020-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15980316.2020.1825537","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44488299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}