Organic Electronics最新文献

{"title":"Photo- and electroluminescent properties of V-shaped fused-biscoumarins containing tert-butyl group modified imidazole/carbazole groups","authors":"Rongjing Liu ,&nbsp;Tianzhi Yu ,&nbsp;Ruige Su ,&nbsp;Yuling Zhao ,&nbsp;Di Zhang ,&nbsp;Shuomei Zhang ,&nbsp;Wenming Su","doi":"10.1016/j.orgel.2025.107208","DOIUrl":"10.1016/j.orgel.2025.107208","url":null,"abstract":"<div><div>The unique molecular structure of fused-biscoumarins endows them with intriguing photophysical properties, making some of them excellent fluorophores. However, their poor solubility limits their application in the solution-processable organic light-emitting diodes (OLEDs). In this work, to improve the solubility of the fused-biscoumarins for the solution-processable OLEDs, two new V-shaped fused-biscoumarins containing <em>tert</em>-butyl group modified imidazole/carbazole groups, <strong>VBC-IM</strong> and <strong>VBC-BuCz</strong>, were successfully synthesized and characterized. Both compounds exhibit intense green emission in dichloromethane solution and good thermal stability. In the absence of the hole-transporting layers, the doped devices using the solution-processed emitting layers of CBP:<strong>VBC-IM</strong> or <strong>VBC-BuCz</strong> emit green emission with the maximum external quantum efficiency (EQE_max) of 1.63 % and 1.82 %, and the maximum luminance (L_max) of 2059 cd/m² and 2796 cd/m², respectively.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"139 ","pages":"Article 107208"},"PeriodicalIF":2.7,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143351016","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":"Design of donor-acceptor-acceptor (D-A-A′)-type fluorescence emitters based on benzothiadiazole with the hybridized local and charge-transfer (HLCT) excited state feature for green to deep-red emitting OLEDs","authors":"Shipan Xu ,&nbsp;Xuyang Du ,&nbsp;Xiaolong Yang ,&nbsp;Huaiteng Hang ,&nbsp;Jun Xi ,&nbsp;Guijiang Zhou ,&nbsp;Yuanhui Sun","doi":"10.1016/j.orgel.2024.107182","DOIUrl":"10.1016/j.orgel.2024.107182","url":null,"abstract":"<div><div>Organic light-emitting diodes (OLEDs) have significant applications in solid-state lightings and flat-panel displays. The development of novel organic emitters to meet the demands of high-performance OLEDs is attracting much attention. The electron withdrawing group benzothiadiazole (BTZ) is widely used in organic emitters due to its rigid planar structure which will benefit the emission performance. At present, the chemical structures of organic emitters based on BTZ skeleton are mostly dominated by the symmetric D-A-D configuration. Herein, we designed and synthesized a serial of asymmetric donor-acceptor-acceptor (D-A-A′)-type fluorescence emitters with the hybridized local and charge-transfer (HLCT) excited state feature. Due to its extended π-conjugation, the D-A-A′ type molecular architecture is conducive to enhancing intramolecular charge transfer and achieving redshift of emitter. Notably, the emission of OLED devices can be finely tuned from green to deep red by varying the doping concentrations of these fluorescent emitters within the host material, thereby enabling a broad spectrum of light colors. Moreover, it is worth highlighting that the introduction of triphenylamine groups can enable devices at much higher doping levels to achieve higher EQEs. Compared with the maximum EQE of 3.1 % for the10 wt% doped OLED based on 7b, the maximum EQEs of devices based on 7b at the doping concentration of 50 wt% and 100 wt% increase to 4.8 % and 3.5 %, respectively. Especially, the non-doped OLED based on 7b exhibits excellent red color purity with the CIE coordinate of (0.63, 0.36), which is very close to the Rec. 709 standard red color CIE coordinate (0.64, 0.33).</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"137 ","pages":"Article 107182"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172726","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":"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":"Perovskite solar cells with boosted device performance through the incorporation of formamidine acetate processing additives","authors":"Lei Liu ,&nbsp;Xiyao Zhang ,&nbsp;Lening Shen ,&nbsp;Zikun Cao ,&nbsp;Zichen Ling ,&nbsp;He Wang ,&nbsp;Qixin Zhou ,&nbsp;Xiong Gong","doi":"10.1016/j.orgel.2024.107177","DOIUrl":"10.1016/j.orgel.2024.107177","url":null,"abstract":"<div><div>Metal halide perovskites are renowned for promising photovoltaic materials for approaching cost-effective solar cells. The prevalent method for crafting metal halide perovskite thin film leads to extensive defects and fragile interfacial contacts, resulting in severe non-radiative charge carrier recombination and ion migration, consequently decreasing both efficiency and stability of perovskite solar cells. In this study, we report enhanced efficiency and stability of perovskite solar cells with suppressed photocurrent hysteresis through the incorporation of formamidine acetate as the processing additive in the preparation of metal halide perovskite thin film. Systematically studies indicate that the formamidine acetate processing additives could enlarge the crystallinity and effectively suppress the defect as well, resulting in boosted and balanced charge transport of the resultant metal halide perovskite thin film. As a result, the perovskite solar cells based on the metal halide perovskite thin film processed with the formamidine acetate additives exhibit 22.29 % of power conversion efficiency, which is more than a 17 % enhancement compared to those based on the pristine metal halide perovskite thin film. Moreover, the perovskite solar cells based on the metal halide perovskite thin film processed with the formamidine acetate additives could maintain its 50 % initial efficiency value for nearly 1400 h of operation and suppressed photocurrent hysteresis. Our studies present an effective strategy to approach high-performance perovskite solar cells.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"137 ","pages":"Article 107177"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172725","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":"Approaches for white organic light-emitting diode via solution-processed blue and yellow TADF emitters: Charge balance and host-guest interactions in a single emission layer","authors":"Emmanuel Santos Moraes,&nbsp;José Carlos Germino,&nbsp;Luiz Pereira","doi":"10.1016/j.orgel.2024.107175","DOIUrl":"10.1016/j.orgel.2024.107175","url":null,"abstract":"<div><div><span><figure><span><img><ol><li><span><span>Download: <span>Download high-res image (233KB)</span></span></span></li><li><span><span>Download: <span>Download full-size image</span></span></span></li></ol></span></figure></span>Although OLEDs are widely employed nowadays for display technology devices, their application for room-lighting illumination remains a challenge due to the cost-effectiveness issues, mainly related to device fabrication. In this sense, the present study investigates the optimization of blue-emitting TADF (DMOC-DPS) and yellow-emitting TADF (TXO-TPA) compounds in solution-processed OLEDs to achieve efficient white light emission in a two-organic layer device. Four different host materials were studied, aiming to balance the charge mobility of holes and electrons. The host materials used include (in %wt.) a 1:1 mixture of mCP and DPEPO (<strong>HOST1</strong>), a 3:2 mixture of PVK and DPEPO (<strong>HOST2</strong>), a 3:2 mixture of PVK and mCP (<strong>HOST3</strong>), and a 3:2 mixture of PVK and butyl-PBD (<strong>HOST4</strong>). The experimental results obtained from the solution-processed OLEDs indicate that DMOC-DPS is predominantly a hole transport material, and hosts with predominantly n-type character, such as <strong>HOST1</strong> and <strong>HOST4</strong>, resulting in the most efficient white-OLEDs by the most balanced charge mobility. With structure optimization, WOLEDs achieved 6.43 % EQE with a brightness of 2621 cd/m² (not integrated) and 6.06 % EQE with a brightness of 1986 cd/m² for <strong>HOST4</strong> and <strong>HOST1</strong>, respectively. The emission characteristics were influenced by host materials characteristics, with blue and yellow emissions being fine-tuned to produce complementary colors. This study highlights the critical role of charge mobility balance in the emissive layer and demonstrates the potential of independently optimizing blue and yellow TADF components for high-performance WOLEDs suitable for indoor lighting applications.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"137 ","pages":"Article 107175"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172723","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":"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}