Organic Electronics最新文献

{"title":"Computational screening of multi-resonance thermally activated delayed fluorescence (MR-TADF) molecules for lasing application","authors":"Rongrong Li ,&nbsp;Zhigang Shuai","doi":"10.1016/j.orgel.2024.107095","DOIUrl":"10.1016/j.orgel.2024.107095","url":null,"abstract":"<div><p>Multi-resonance thermally activated delayed fluorescence (MR-TADF) molecules charactering large emission oscillator strengths, effective reverse intersystem crossing (RISC), and narrow emission spectral width, have great potential as laser materials. We propose a molecular descriptor for quick screening MR-TADF molecules as laser candidate materials, <em>A =</em> <span><math><mrow><msub><mrow><mo>Δ</mo><mi>E</mi></mrow><mtext>ST</mtext></msub><msubsup><mi>σ</mi><mtext>eff</mtext><mrow><mtext>net</mtext><mo>,</mo><mtext>opt</mtext></mrow></msubsup></mrow></math></span>, namely, the product of singlet-triplet energy gap and the optical pumping net stimulated emission cross section. These quantities can be calculated by combining quantum chemistry package Gaussian and our own MOMAP program. Through extensive computations benchmarked with existing experiments, we suggest that <em>A</em> value should be larger than 0.311 ⨉ 10⁻¹⁷ cm² eV for promising lasing molecules. We virtually designed 119 molecules with MR-TADF property, and based on our theoretical protocol by considering descriptor <em>A</em>, we are able to select 10 molecules as lasing molecules. We then further screen out 2 molecules through analyzing the spectral overlap, indicating that only eight molecules are prospective candidates for laser materials. Particularly, we find that ADBNA-Me-BPy molecule possesses large radiative decay rate and large reverse intersystem crossing rate, 1.90 × 10⁶ s⁻¹ and 1.01 × 10⁸ s⁻¹, respectively, implying a low lasing threshold, promising for electrically pumped lasing.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"132 ","pages":"Article 107095"},"PeriodicalIF":2.7,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141638269","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":"Simulation of neural functions based on organic semiconductor/MXene synaptic transistors","authors":"Hongying Qiu,&nbsp;Shuqiong Lan,&nbsp;Qiubao Lin,&nbsp;Huili Zhu,&nbsp;Wenliang Liao,&nbsp;Lan Yang","doi":"10.1016/j.orgel.2024.107090","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107090","url":null,"abstract":"<div><p>Artificial synaptic devices, which are the basic units of neuromorphic computing systems, can perform signal processing with low power consumption. Organic synaptic transistors have attracted significant attention owing to their lightweight and good compatibility with flexible substrates. As per the current state of research both domestically and internationally, the majority of the existing organic synaptic transistors are based on floating gate structures, electret configurations, ferroelectric types. Furthermore, additional capture layers are required for the preparation of these devices. Two-dimensional MXenes have great potential in the preparation of synaptic transistors owing to their efficient multiple energy storage capabilities, excellent metallic conductivity, abundant surface functional groups, hydrophilicity, and layered structure. Therefore, high-performance synaptic transistors based on the two-dimensional material MXene were developed in this study. These transistors not only exhibited excellent memory performance with a memory window above 20 V, but also successfully simulated typical synaptic behaviors, including excitatory postsynaptic current/inhibitory postsynaptic current (EPSC/IPSC), paired-pulse facilitation/paired-pulse depression (PPF/PPD), and long-term plasticity (LTP). Synaptic transistors based on MXenes represent a promising approach for the preparation of high-performance organic synaptic transistors.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107090"},"PeriodicalIF":2.7,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583348","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":"Enhanced resistive switching behaviors of organic resistive random access memory devices by adding polyethyleneimine interlayer","authors":"Mehr Khalid Rahmani ,&nbsp;Sobia Ali Khan ,&nbsp;Dae-Myeong Geum ,&nbsp;Hyuntak Jeon ,&nbsp;Seong Yeon Park ,&nbsp;Changhun Yun ,&nbsp;Moon Hee Kang","doi":"10.1016/j.orgel.2024.107089","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107089","url":null,"abstract":"<div><p>Organic nonvolatile memory devices have garnered significant attention as next-generation electrical memory units owing to their potential for low-cost and straightforward fabrication through a solution process. In this study, we successfully fabricated fully solution-processed organic resistive random access memory (RRAM) devices using poly(3-hexylthiophene-2,5-diyl) <u>(P3HT)</u> and [6,6]-phenyl-C61-butyric acid methyl ester <u>(PCBM)</u> as the resistive switching (RS) layer, with poly(3,4-ethylene-dioxythiophene):poly(styrene sulfonate) <u>(PEDOT:PSS)</u> employed as the top electrode. Additionally, to enhance performance further, a polyethyleneimine (PEIE) interlayer was introduced between the bottom electrode and the P3HT:PCBM RS layer. The resulting organic RRAM devices with the PEIE interlayer exhibited bipolar resistive switching, with improved endurance increasing from 50 to 100 cycles, a retention time of 10³ s, and a low SET voltage of 0.7 V. The organic RRAM devices featuring the PEIE interlayer demonstrated superior RS performance attributed to the higher Schottky barrier at the interface between the bottom electrode and the active switching layer, creating an asymmetric structure. I–V curve fitting confirmed that the potential switching mechanism involved Schottky emission in the high-resistance state and Ohmic conduction in the low-resistance state. Our findings suggest that organic RRAM devices with a PEIE interlayer hold promise for stable nonvolatile memory applications.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"132 ","pages":"Article 107089"},"PeriodicalIF":2.7,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605312","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":"High sensitivity flexible organic X-ray detectors with minor TIPS-pentacene/insulator polymer blend active layer","authors":"Zhao Hao,&nbsp;Yi Li,&nbsp;Yuanjian Deng,&nbsp;Zehua Chen,&nbsp;Jie Liang,&nbsp;Xiuzhen Lu,&nbsp;Jianhua Zhang","doi":"10.1016/j.orgel.2024.107088","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107088","url":null,"abstract":"<div><p>A new class of flexible X-ray sensor in which there is a vertical structure with the active layer of minor 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) blending into styrene-ethylene-butadiene-styrene (SEBS) has been developed. The minor TIPS-pentacene to enhance the sensitivity of 1137.2 μCGy_air⁻¹ cm⁻² and low detection limit of 47.91 nGy_air s⁻¹ because of the higher attenuation coefficient and photocurrent gain effect in the hybrid active layer. The stability and flexibility of this organic detector are attributed to the plasticity of SEBS and encapsulation of TIPS-pentacene. This work highlights the potential exploitation of high-performance future innovative flexible and highly sensitive direct X-ray detectors.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107088"},"PeriodicalIF":2.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542398","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":"Improving efficiency in RGB phosphorescent and white organic light emitting diodes via donor-spiro-boron acceptor host materials","authors":"Aziz Khan ,&nbsp;Xing Chen ,&nbsp;Man-Keung Fung ,&nbsp;Zhiming Wang","doi":"10.1016/j.orgel.2024.107086","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107086","url":null,"abstract":"<div><p>The universal host material with boron acceptor core structure is exceptionally sparse to be designed for red, green, and blue in efficient phosphorescent organic light emitting diodes (PhOLEDs) accompanying white OLEDs, possessing indistinguishable device feature. Herein, two boron acceptors spiro-host materials namely 1'-(4-(dimesitylboranyl)phenyl)-10-phenyl-10H-spiro[acridine-9,9′-fluorene] <strong>(TPA-PBM)</strong> and 1-(4-(dimesitylboranyl)phenyl)-3′,6′-dimethylspiro[fluorene-9,8′-indolo[3,2,1-de]acridine] (<strong>2MeCz-PBM)</strong> were designed and synthesized. The designed rigid donor strategy exhibited good device performance among the reported boron donor-spiro-acceptor (D-spiro-A) skeleton for organic light emitting diodes (OLEDs). In particular, we fabricate RGB three-color phosphorescent OLEDs based on <strong>TPA-PBM</strong> and <strong>2MeCz-PBM.</strong> The red devices exhibit a maximum external quantum efficiency (EQE) of nearly 28 % (26.8 % for <strong>TPA-PBM</strong> and 27.5 % for <strong>2MeCz-PBM</strong>), with an electroluminescence spectrum at 608 nm. The green/blue devices obtain maximum EQEs of 21.2 %/15.3 % and 21.8 % 17.3 %, for <strong>TPA-PBM</strong> and <strong>2MeCz-PBM</strong>, respectively. Furthermore, green devices display an extremely low efficiency roll-off with decreasing 1 % and 3 % at luminance of 5000 cd m⁻². Additionally, the two-color white OLED using <strong>2MeCz-PBM</strong> exhibits EQE_max and PE_max are 24.5 % and 62.9 lm W⁻¹ respectively, the EQE remain 23.8 % at commercial lighting brightness of 1000 cd m⁻². The WOLED also shows a stable white spectrum with CIE varying range of (0.41, 0.47) to (0.39, 0.46) at 100 cd m⁻² to 15000 cd m⁻². All obtained results confirmed that our targeted molecules have advantage of carrier balance and efficient charge recombination, which might replace many other commercial host materials.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107086"},"PeriodicalIF":2.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141485821","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":"Progressive quenching of luminescence from quantum dot thin films in proximity with ZnMgO in unencapsulated stacks","authors":"Atefeh Ghorbani,&nbsp;Hany Aziz","doi":"10.1016/j.orgel.2024.107087","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107087","url":null,"abstract":"<div><p>ZnMgO nanoparticles (NPs) are being increasingly used as the electron transport layer (ETL) in state-of-the-art quantum-dot light-emitting devices (QLEDs) instead of ZnO. However, the impact of ZnMgO on the luminescence properties of quantum dots (QDs) is much less understood. Here, we compare ZnMgO and ZnO NPs for their quenching effect on Cd-based QDs photoluminescence (PL), immediately and over time. Time-resolved photoluminescence (TRPL) and steady-state PL results show that ZnMgO NPs decreases the QDs’ luminescence more than ZnO NPs and that the behavior continues progressively over time. The surface topography of the samples containing different ETLs is studied using atomic force microscopy (AFM) and optical PL images. Additionally, time of flight secondary ion mass spectroscopy (TOF-SIMS) measurements are conducted to investigate the potential diffusion of some species from ETL into the QDs layer. The results confirm that morphological changes and out-diffusion of some species from the ZnMgO layer can likely play a role in the QDs PL quenching. This study sheds light on the limitations of ZnMgO for the long-term stability of QLEDs, specifically for blue QLEDs where using ZnMgO is essential for efficient electron injection.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107087"},"PeriodicalIF":2.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1566119924000983/pdfft?md5=727a6e599d1c56c4cc38163fa67ddb44&pid=1-s2.0-S1566119924000983-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542397","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":"Manipulating the photophysical properties of multi-donor molecules for fast reverse intersystem crossing in solution-processed OLED devices","authors":"Hengwei Tian ,&nbsp;Xuming Zhuang ,&nbsp;Zhi-Ping Yan ,&nbsp;Hai Bi ,&nbsp;Zhiqiang Li ,&nbsp;Yue Wang ,&nbsp;Yanping Huo","doi":"10.1016/j.orgel.2024.107085","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107085","url":null,"abstract":"<div><p>The slow reverse intersystem crossing (RISC) rate in thermally activated delayed fluorescence (TADF) emitters result in extended exciton lifetime and pronounced efficiency loss at high luminance level. To address this limitation, we have developed and characterized a series of novel compounds featuring triazine cores substituted with <em>tert</em>-butyl carbazole moieties at various positions and quantities. The objective here is to fine-tune the charge transfer properties, thereby enhancing the efficiency of the RISC process. Our studies reveal that through-space charge transfer is more effective than long-range through-bond charge transfer in minimizing the singlet-triplet energy gap and accelerating RISC. The optimized compound, <strong>4tCzTrz</strong>, exhibits an exceptionally fast RISC rate of 1.02 × 10⁷ s⁻¹ and a high photoluminescence quantum yield of up to 100 %. Solution-processed organic light-emitting diodes (OLEDs) incorporating this molecule have achieved outstanding maximum external quantum efficiencies of around 20 %, whether used as an emitter directly or as a sensitizer to boost overall emission efficiency.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107085"},"PeriodicalIF":2.7,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141485822","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":"Spirobifluorene-appended multi-resonance thermally activated delayed fluorescence emitter for efficient narrowband blue OLEDs with suppressed ACQ effect","authors":"Jia-Chen Li ,&nbsp;Zhang-Li Cheng ,&nbsp;Jie Li ,&nbsp;Hui Wang ,&nbsp;Feng Huang ,&nbsp;Ying-Chun Cheng ,&nbsp;Hao Wu ,&nbsp;Xin Xiong ,&nbsp;Jia Yu ,&nbsp;Hua-Yue Wu ,&nbsp;Jie-Yu Zhou ,&nbsp;Kai Wang ,&nbsp;Xiao-Hong Zhang ,&nbsp;Jun Ye","doi":"10.1016/j.orgel.2024.107084","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107084","url":null,"abstract":"<div><p>Multi-resonance (MR) thermally activated delayed fluorescence (TADF) materials with planar rigidity show great potential as emitters in organic light-emitting diodes (OLEDs) due to their high photoluminescence quantum yields and narrowband emission. However, their strong intermolecular interaction trends usually result in redshifted and broadened emission spectra as well as low device efficiencies due to the aggregation-caused quenching (ACQ) effect. In this paper, a bulky spirobifluorene unit was appended onto an asymmetric carbazole/diphenylamine-embedded MR skeleton to relieve such trends, thus affording a new MR-TADF blue emitter, BNSF-1. Introducing spirobifluorene significantly relieves the intermolecular interaction trends of MR backbones without affecting their original photophysical properties. The corresponding sensitizer-free OLED devices based on BNSF-1 exhibit narrowband sky-blue electroluminescence peaking at 475 nm with a full width at half-maximum of 25 nm, as well as a maximum external quantum efficiency of 25.9 %. More importantly, BNSF-1 exhibited negligible spectral broadening and ACQ trends as the doping ratio increased. Our work provides a feasible method for constructing doping concentration-insensitive MR-TADF emitters.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107084"},"PeriodicalIF":3.2,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141325023","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":"Photophysics and thermally activated delayed fluorescence (TADF) of fullerene C70 and C70 methano and pseudodihydro monoadducts: A comparative study","authors":"Tiago Palmeira ,&nbsp;Célia Santos ,&nbsp;Mario N. Berberan-Santos","doi":"10.1016/j.orgel.2024.107083","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107083","url":null,"abstract":"<div><p>A comparative study of the photophysical properties of pristine C₇₀ and two C₇₀ derivatives, including their thermally activated delayed fluorescence (TADF) is reported. It is observed that the addition of a substituent group to the C₇₀ cage-like structure changes both the radiative and the nonradiative rate constants, the change being more pronounced for the nonradiative processes (S₁→S₀ internal conversion and S₁→T₁ and T₁→S₀ intersystem crossings). A new method of TADF analysis (global analysis of time-resolved and steady-state data) is presented and applied. Both derivatives are found to display a less efficient TADF when compared with C₇₀.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107083"},"PeriodicalIF":3.2,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1566119924000946/pdfft?md5=223b1078cc1efff753252dcaf127415b&pid=1-s2.0-S1566119924000946-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141314272","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":"Enhanced synaptic behavior of neuromorphic device based on organic electrochemical transistors by adding Aminosilane","authors":"Dae-Hee Kim ,&nbsp;Jiyoul Lee ,&nbsp;Yonghee Kim ,&nbsp;Hocheon Yoo ,&nbsp;Eun Kwang Lee","doi":"10.1016/j.orgel.2024.107076","DOIUrl":"https://doi.org/10.1016/j.orgel.2024.107076","url":null,"abstract":"<div><p>Herein, we propose a strategy to enhance the synaptic behavior of neuromorphic devices based on organic electrochemical transistors (OECT) by introducing (3-aminopropyl)triethoxysilane (APT) into the conjugated polymer film channel. Various film analyses utilizing optical and atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy revealed that the addition of APT to the poly (3-hexylthiophene) (P3HT) film facilitated the formation of highly crystalline P3HT aggregation, thereby suppressing film degradation induced by repetitive ion injection and ejection under gate bias. Furthermore, electrical characterization of the OECT devices incorporating P3HT channels demonstrated an expanded hysteresis region and improved memory characteristics upon APT addition, which contains functional groups with high electron density, favorably influencing synaptic plasticity features such as short-term plasticity (STP), long-term plasticity (LTP), short-term memory (STM), and long-term memory (LTM). Consequently, it led to the fortification and resilience of synaptic behavior in OECTs, positioning them as a promising candidate for neuromorphic devices.</p></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"131 ","pages":"Article 107076"},"PeriodicalIF":3.2,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141328951","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}