Organic Electronics最新文献

{"title":"Flexible electrically erasable nonvolatile organic memory utilizing a solution-processed transparent polyethylene oxide: PCBM blend film","authors":"Xiaoyan Tu ,&nbsp;Pengtian Liu ,&nbsp;Gong Zhang,&nbsp;Guozhen Bai,&nbsp;Zilong Wang,&nbsp;Zhidong Lou,&nbsp;Yanbing Hou,&nbsp;Feng Teng,&nbsp;Yufeng Hu","doi":"10.1016/j.orgel.2024.107179","DOIUrl":"10.1016/j.orgel.2024.107179","url":null,"abstract":"<div><div>Organic flexible transparent electrically erasable nonvolatile memory presents significant potential for integration into bendable, stretchable, and transparent electronic devices. This capability unlocks a broad spectrum of potential applications in various fields, including wearable devices, medical equipment, and smart buildings. Polyethylene oxide (PEO) is a promising candidate for these devices due to its broad band gap, mechanical flexibility, chemical and thermal stability, water solubility, biocompatibility, and low cost. This study demonstrates a flexible transparent nonvolatile memory device utilizing a PEO and fullerene blend film. The average transmittance of the PET/ITO/PEO:PC₆₁BM multilayer stack exceeds 86% in the optically visible range from 380 nm to 800 nm. The PET/ITO/PEO:PC₆₁BM/Al device exhibits typical nonvolatile memory behavior, with the maximum electrical ON/OFF state ratio exceeding 10³. Furthermore, retention tests for both ON and OFF states, along with bending cycle measurements and Write-Read-Erase-Read cycle endurance tests, indicate that the device remains stable under ambient conditions. The electrical conduction transition mechanisms are attributed to the formation of carbon filaments by PCBM aggregates.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"137 ","pages":"Article 107179"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subthreshold slope optimization for pentacene based organic tunnel field effect transistor","authors":"Nivedha E,&nbsp;Rajesh Agarwal","doi":"10.1016/j.orgel.2024.107176","DOIUrl":"10.1016/j.orgel.2024.107176","url":null,"abstract":"<div><div>Conventional Organic Thin Film Transistors (OTFTs) face significant challenges. Short-channel effects prevent current saturation when scaled to the nanoscale, while the thermionic transport mechanism limits the subthreshold swing to values above 60 mV/dec. To overcome these limitations, a Doped Lateral Organic Tunnel Field Effect Transistor (DL O-TuFET) is proposed. This work examines the influence of source and drain doping on device performance. The higher source doping enhances tunneling probability, while moderate drain doping reduces OFF-current and improves subthreshold swing. Furthermore, the impact of trap density in the active material on device characteristics is investigated. Key performance metrics, including threshold voltage, subthreshold swing, ON/OFF ratio, and RF parameters, are quantitatively analyzed. Simulations using Silvaco TCAD reveal that an optimized source and drain doping of 1 x 10²¹ cm⁻³ and 1 x 10¹⁹ cm⁻³, respectively, yields promising results. The device exhibits a threshold voltage of −0.963 V, a subthreshold swing of 12.5 mV/decade, an ON/OFF ratio in the range of 10¹⁷, a maximum electric field of 5.41 × 10⁷ V/cm, and a maximum band-to-band tunneling rate of 7.94 x 10³²/cm³s. These values contribute to a maximum ON-current of 83.6 μA, making the DL O-TuFET a viable alternative to conventional OTFTs. Moreover, a maximum cut-off frequency of 0.66 GHz demonstrates its suitability for higher-speed applications.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"137 ","pages":"Article 107176"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitigating slow reverse ISC rates in TAPC:PBD exciplex via rapid Förster energy transfer to TTPA","authors":"Lucy A. Weatherill ,&nbsp;Ross Milverton ,&nbsp;Piotr Pander ,&nbsp;Fernando B. Dias","doi":"10.1016/j.orgel.2024.107180","DOIUrl":"10.1016/j.orgel.2024.107180","url":null,"abstract":"<div><div>There have been many advances in the development of thermally activated delayed fluorescence (TADF) materials for organic light emitting diode (OLED) applications in recent years. In particular, intramolecular exciplex systems have been highly studied and found to produce OLED devices of high external quantum efficiency (EQE) due to triplet harvesting via TADF. The proposed next generation of OLEDs uses hyperfluorescence to overcome the problem of broad emission associated with exciplexes. This process involves Förster resonance energy transfer (FRET) from the TADF host to a fluorescent dopant. In this work we revisited the photophysics of the <strong>TAPC:PBD</strong> exciplex (formed between the electron donor di-[4-(<em>N</em>,<em>N</em>-di-<em>p</em>-tolyl-amino)-phenyl]cyclohexane (<strong>TAPC</strong>) and the electron acceptor, 2-(4-biphenyl)-5-(4-<em>tert</em>-butylphenyl)-1,3,4-oxadiazole (<strong>PBD</strong>)) as a host capable of simultaneously performing triplet harvesting and work as a donor transferring energy to a bright fluorescent emitter. The aim is to investigate the interplay between energy transfer and intersystem crossing in this hyperfluorescence system. Contrarily to previous findings, films of the <strong>TAPC</strong>:<strong>PBD</strong> blend show relatively slow reverse intersystem crossing rate (RISC) and weak luminescence efficiency (PLQY). Despite this, when doped with the strong fluorescent emitter <strong>TTPA</strong>, the luminescence quantum yield is greatly improved due to the highly efficient energy transfer rate from <strong>TAPC</strong>:<strong>PBD</strong> to <strong>TTPA</strong>. The rapid FRET from the exciplex to the fluorescent emitter overcomes the non-radiative losses affecting the luminescence efficiency of the blend. This study shows that the hyperfluorescence mechanism not only allows colour purity in OLEDs to be optimised, but also facilitates suppressing major loss mechanisms affecting luminescence efficiency, thus creating conditions to maximizing EQE.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"137 ","pages":"Article 107180"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface recombination in organic solar cells: Intrinsic vs. doped active layer","authors":"Gulnur Akhtanova ,&nbsp;Hryhorii P. Parkhomenko ,&nbsp;Joachim Vollbrecht ,&nbsp;Andrii I. Mostovyi ,&nbsp;Nora Schopp ,&nbsp;Viktor Brus","doi":"10.1016/j.orgel.2024.107183","DOIUrl":"10.1016/j.orgel.2024.107183","url":null,"abstract":"<div><div>This study extends the analytical model of surface recombination in organic solar cells with an intrinsic active bulk-heterojunction layer. The key finding of the developed multi-mechanism recombination model accounting for the intrinsic active layer is that the slope of <em>V</em>_<em>OC</em> vs. ln(Light Intensity) cannot be lower than 1.0 kT<em>/q</em> even at the extremely high concentrations of surface traps. We revealed the difference in recombination-related parameters determined in the scope of the multi-mechanism recombination model for the doped or intrinsic active layer and highlighted the importance of identifying the doping level of the active layer material. This is demonstrated by a synergy of comprehensive simulation and experimental analysis of organic solar cells with donor: acceptor blends: (PM6:Y6, PTB7-Th:COTIC-4F, PTB7-Th:O-IDTBR and PTB7-Th:ITIC-4F).</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"137 ","pages":"Article 107183"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 low-toxicity precursor solvent system enabled green fabrication of high-performance perovskite solar cells","authors":"Yaoyao Song,&nbsp;Huiyin Zhang,&nbsp;Shixian Huang,&nbsp;Yunzhao Sun,&nbsp;Mengfan Liu,&nbsp;Kai Pang","doi":"10.1016/j.orgel.2025.107206","DOIUrl":"10.1016/j.orgel.2025.107206","url":null,"abstract":"<div><div>The commercialization of perovskite solar cells (PSCs) technology is in full swing, but the ecotoxicity of the solvents involved in perovskite processing remains a barrier. Herein, a low-toxicity 1,3-dimethyl-2-imidazolidinone(dimethyl sulfoxide) solvent system, abbreviated as DMI(DMSO), has been designed to support the green fabrication of perovskite films and PSCs. Both DMI and DMSO can be proposed as less-toxic solvents. By optimizing the volume ratio of DMSO cosolvent in DMI(DMSO) solvent system, the morphologies, optical properties and photovoltaic performance of perovskite films can be well modulated. The delivered planar PSCs achieved a best power conversion efficiency of up to 20.24 %, comparable to those of devices based on the traditional solvent systems. This work provides a feasible way to produce scalable PSCs with high efficiency using an environmentally benign solvent system.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"139 ","pages":"Article 107206"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143352713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescence properties and mechanism studies of thermally activated delayed fluorescence molecules","authors":"Zhimin Wu,&nbsp;Xiaofei Wang,&nbsp;Rui Li,&nbsp;Jiaxin Zhou,&nbsp;Ying Cao,&nbsp;Yuzhi Song,&nbsp;Jianzhong Fan,&nbsp;Chuan-Kui Wang,&nbsp;Lili Lin,&nbsp;Zhongjie Wang","doi":"10.1016/j.orgel.2025.107205","DOIUrl":"10.1016/j.orgel.2025.107205","url":null,"abstract":"<div><div>Thermally activated delayed fluorescence (TADF) has gained significant attention as a key mechanism in developing highly efficient organic light-emitting diodes (OLEDs). This review consolidates recent advancements in the theoretical exploration of TADF mechanisms, emphasizing the intricate donor-acceptor (D-A) interactions, the influence of various donor groups on the optical properties, and the behavior of luminescence across different phases. Employing a multiscale simulation, which encompasses density functional theory (DFT) and time-dependent DFT (TD-DFT), this paper elucidates the electroluminescence mechanisms of TADF molecules in both amorphous and crystalline states. The study highlights the significant impact of solid-state interactions on the luminescent properties of TADF materials, offering a comprehensive understanding of the structure-property relationships. These theoretical insights provide a robust foundation for designing next-generation TADF materials with optimized performance, addressing the existing challenges in achieving efficient blue and red light emitters for practical applications in OLED technology. Through this review, we aim to present a coherent overview of the current state of TADF research, identify the critical factors influencing luminescence, and propose strategic directions for future research to further enhance the efficacy and applicability of TADF-based OLEDs.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"139 ","pages":"Article 107205"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143283856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulation of film morphology and vertical phase separation for inverted organic solar cells via a volatile solvent additive","authors":"Minghui Huang ,&nbsp;Xueting Yi ,&nbsp;Zekun Liu ,&nbsp;Mengan Zhao ,&nbsp;Jiang Wu ,&nbsp;Yingying Fu ,&nbsp;Zhiyuan Xie","doi":"10.1016/j.orgel.2025.107207","DOIUrl":"10.1016/j.orgel.2025.107207","url":null,"abstract":"<div><div>The additives play a vital role in both photovoltaic performance and device stability of organic solar cells (OSCs). Although solvent additives have been extensively utilized in conventional OSC structures to adjust film morphology and regulate crystallization behavior of photoactive materials, their attempt and specific roles in inverted OSCs remain rarely explored. Herein, a kind of halogen-free and volatile solvent additive methyl benzoate (MB) is selected for optimization of the inverted OSCs. It is found that MB could produce distinct positive interaction with L8-BO acceptors, leading to enhanced molecular crystallization and appropriate microstructure in PM6:L8-BO active layers. In addition, the MB-processed PM6:L8-BO films exhibit an optimized vertical phase distribution driven by differences of miscibility between components. The improved horizontal and vertical morphology facilitates charge transport and suppresses charge recombination in the resultant inverted OSCs. Consequently, the power conversion efficiency (PCE) increases from 15.88 % to 17.08 %. Furthermore, the volatile MB with a low boiling point and high vapor pressure could prevent residual in active layers and avoid thermal degradation of OSCs. Benefiting from synergistic effects of the positive volatility and improved acceptor crystallinity, the MB-processed devices demonstrate enhanced thermal stability compared to the control devices. This work highlights the potential of volatile solvent additives for fabricating efficient and stable inverted OSC devices.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"139 ","pages":"Article 107207"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence for localized trap formation during TADF OLED degradation","authors":"Edoardo Stanzani ,&nbsp;Stefano Sem ,&nbsp;Simon Züfle ,&nbsp;Beat Ruhstaller ,&nbsp;Sandra Jenatsch","doi":"10.1016/j.orgel.2025.107204","DOIUrl":"10.1016/j.orgel.2025.107204","url":null,"abstract":"<div><div>Thermally activated delayed fluorescence (TADF) emitters attract interest as organic light-emitting diode (OLED) materials with potentially 100 % internal quantum efficiency (IQE). Their application in commercial displays is still hindered due to the not yet sufficient operational stability. We analyze the degradation mechanism in a TADF OLED by combining intermittent electro-optical characterization with device simulations. Evidence for the generation of trap states is found in capacitance-voltage (C-V) measurements. To explain both the C-V as well as the current-voltage and the capacitance-frequency evolution during prolonged operation times, at least two types of trap states are necessary. Device simulations are used to assess their location within the multilayer structure. It is found that both hole and electron traps at the HTL/EML interface can explain the experimental data. A quantitative comparison of simulations and experimental data reveal a hole and electron trap density of 8 ∙ 10¹⁸ cm⁻³ and 8 ∙ 10¹⁷ cm⁻³, respectively, at LT80 (the time at which the luminance has dropped to 80 % of its initial value). The main driver for the current efficiency decrease are the hole traps inside the HTL. The findings unravel the weak points in the TADF OLED and thereby guide further development to enhance device stability.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"139 ","pages":"Article 107204"},"PeriodicalIF":2.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen and sulfur Co-doped carbon dots with excellent fluorescent thermal stability for anti-counterfeiting and information encryption","authors":"Nouman Ahmed ,&nbsp;Manzoor Hussain ,&nbsp;Aumber abbas ,&nbsp;Tauqeer Haidar Qamar ,&nbsp;Sibt ul Hassan ,&nbsp;Pengkun Xia ,&nbsp;Lei Ma ,&nbsp;Xiaohui Gao ,&nbsp;Lianwen Deng","doi":"10.1016/j.orgel.2025.107197","DOIUrl":"10.1016/j.orgel.2025.107197","url":null,"abstract":"<div><div>In this work, a series of nitrogen and sulfur co-doped carbon dots (CDs) were synthesized with high photoluminescence quantum yields (PLQYs) and outstanding thermal stability. With the reaction solvent changing from water, ethanol, methanol, and dimethylformamide (DMF), a significant fluorescence emission with PLQY improvement from 42 %, 33 %, 25 %, and 18 %, respectively, accompanied by a red shift from 430 to 590 nm, (the color changes from blue, green, yellow, and red respectively). Simultaneously, excellent fluorescence stability can also be obtained across temperatures ranging from 15 to 95 °C. Combined with the density functional calculations (DFT) results, the underlying mechanism investigation reveals that the color change of fluorescence emission was probably induced by the increased particle size of CDs and increased graphitic N content. The enhanced thermal stability is induced by the presence of stable surface functional groups, including C=O, C=N, C=S, and -NH, among others, contributing to improved hydrophilicity, regulated particle aggregation, and mitigated thermal oxidation by limiting oxygen diffusion to fluorescent hubs. Notably, the obtained outstanding optical properties finally render these multicolor CDs suitable for information encryption and anti-counterfeiting applications.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"139 ","pages":"Article 107197"},"PeriodicalIF":2.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-high-efficiency white organic light-emitting diodes based on TADF material incorporated efficient exciplex hosts","authors":"Zi-Qi Chen ,&nbsp;Han Liu ,&nbsp;Xiao-Jing Wang ,&nbsp;Jian Fan ,&nbsp;Yue-Min Xie ,&nbsp;Man-Keung Fung","doi":"10.1016/j.orgel.2025.107196","DOIUrl":"10.1016/j.orgel.2025.107196","url":null,"abstract":"<div><div>White organic light-emitting diode (WOLED) has been recognized as a healthy light source. However, the device performance is still limited by the hosts or emitters. Herein, multiple-exciplex hosts are developed for WOLEDs, in which a novel exciplex host consisting of a thermally activated delayed fluorescent material, triazine–carbazole (Trz-PhCz), and an electron-transport material, 4,6-bis[3,5-(dipyrid-4-yl)phenyl]-2-methylpyrimidine (B4PyMPM), is adopted for green, yellow, orange and red phosphorescent dopants, of which high external quantum efficiencies (EQEs) of 25.0 %, 30.7 %, 32.5 % and 26.2 %, respectively, are achieved. On the other hand, a high-energy exciplex host consisting of 9,9′-biphenyl-3,3′-diylbis-9H-carbazole (mCBP) and B4PyMPM is designed for the blue emitter, iridium(III)bis(4,6-(difluorophenyl)-pyridinato-N,C2’) picolinate (FIrpic), which guarantees a maximum EQE of 26.3 %. The small exciton energy difference between the mCBP:B4PyMPM and Trz-PhCz:B4PyMPM hosts can facilitate efficient energy transfer between the hosts. As a result, these exciplex hosts facilitate energy-efficient WOLEDs with a maximum EQE, power efficiency and current efficiency of 36.9 %, 137.4 lm W⁻¹ and 106.7 cd A⁻¹, respectively, without using any optical out-coupling techniques, which provides inspiration for the future design of efficient OLEDs.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"139 ","pages":"Article 107196"},"PeriodicalIF":2.7,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}