Pub Date : 2026-01-02DOI: 10.1016/j.orgel.2025.107371
Guo Honghui , Baoming Hou , Huimin Yang , Xiaomin Yin , Yuang Yang , Yuyu Pan , Li Fan , Bing Yang
In this study, we theoretically investigated the luminescence mechanisms and optoelectronic properties of two experimentally red thermally activated delayed fluorescence (TADF) molecules through multiscale calculations combining quantum mechanics/molecular mechanics (QM/MM) methods with molecular dynamics simulations. Based on these findings, we designed two new molecules. Analysis of the structure-property relationship revealed that the rigid molecular structure in the aggregated state substantially suppresses molecular vibrations induced by structural changes, thereby significantly reducing nonradiative transition rates. Furthermore, increasing the axial length of the molecule transformed its luminescent behavior from typical TADF to HLCT. This study not only provides a reliable explanation for experimental observations but also offers valuable insights for the future design of red TADF and HLCT molecules.
{"title":"TADF and HLCT emission switching by changing the intramolecular charge transfer properties through modification of substituent orientation","authors":"Guo Honghui , Baoming Hou , Huimin Yang , Xiaomin Yin , Yuang Yang , Yuyu Pan , Li Fan , Bing Yang","doi":"10.1016/j.orgel.2025.107371","DOIUrl":"10.1016/j.orgel.2025.107371","url":null,"abstract":"<div><div>In this study, we theoretically investigated the luminescence mechanisms and optoelectronic properties of two experimentally red thermally activated delayed fluorescence (TADF) molecules through multiscale calculations combining quantum mechanics/molecular mechanics (QM/MM) methods with molecular dynamics simulations. Based on these findings, we designed two new molecules. Analysis of the structure-property relationship revealed that the rigid molecular structure in the aggregated state substantially suppresses molecular vibrations induced by structural changes, thereby significantly reducing nonradiative transition rates. Furthermore, increasing the axial length of the molecule transformed its luminescent behavior from typical TADF to HLCT. This study not only provides a reliable explanation for experimental observations but also offers valuable insights for the future design of red TADF and HLCT molecules.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"151 ","pages":"Article 107371"},"PeriodicalIF":2.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145898093","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}
Pub Date : 2025-12-24DOI: 10.1016/j.orgel.2025.107369
Xingyu Zang , Qing Zhang , Xiaolong Liu , Tianbao Gong , Jungang Cao , Chenguang Wang , Jinbei Wei
Multiple resonance thermally activated delayed fluorescence (MR-TADF) materials have emerged as highly promising emitters for organic light-emitting diodes (OLEDs), owing to their narrowband emission and exceptional luminescence efficiency. Nevertheless, most MR-TADF emitters suffer from severe efficiency roll-off and insufficient exciton utilization efficiency due to aggregation-caused quenching (ACQ) and intrinsically long triplet exciton lifetimes. To address these limitations, we developed a series of through-space charge transfer (TSCT) TADF sensitizers, which exhibit a minimal singlet-triplet energy gap of 0.06 eV and a rapid reverse intersystem crossing rate (kRISC) of 3.8 × 105 s−1. By employing these TSCT-TADF sensitizers in MR-TADF systems to recycle triplet excitons, the resulting TADF-sensitized fluorescent OLED (TSF-OLED) achieved narrowband green emission with a CIEy coordinate of 0.71, a maximum external quantum efficiency (EQEmax) exceeding 35 %, and a suppressed efficiency roll-off of only 26.9 % at 1000 cd m−2.
多共振热激活延迟荧光（MR-TADF）材料由于其窄带发射和优异的发光效率而成为有机发光二极管（oled）极有前途的发射体。然而，由于聚集引起的猝灭（ACQ）和固有的长三重态激子寿命，大多数MR-TADF发射器存在严重的效率滚降和激子利用效率不足的问题。为了解决这些限制，我们开发了一系列通过空间电荷转移（TSCT） TADF敏化剂，其单重态-三重态能隙最小，为0.06 eV，逆向系统间交叉速率（kRISC）为3.8 × 105 s−1。通过在MR-TADF系统中使用这些TSCT-TADF敏化剂来回收三态激子，所得到的tsct敏化荧光OLED （TSF-OLED）实现了窄带绿色发射，CIEy坐标为0.71，最大外量子效率（EQEmax）超过35%，在1000 cd m−2下抑制效率滚降仅为26.9%。
{"title":"Highly-efficient narrowband green OLEDs with suppressed efficiency roll-off enabled by through-space charge transfer type TADF sensitizers","authors":"Xingyu Zang , Qing Zhang , Xiaolong Liu , Tianbao Gong , Jungang Cao , Chenguang Wang , Jinbei Wei","doi":"10.1016/j.orgel.2025.107369","DOIUrl":"10.1016/j.orgel.2025.107369","url":null,"abstract":"<div><div>Multiple resonance thermally activated delayed fluorescence (MR-TADF) materials have emerged as highly promising emitters for organic light-emitting diodes (OLEDs), owing to their narrowband emission and exceptional luminescence efficiency. Nevertheless, most MR-TADF emitters suffer from severe efficiency roll-off and insufficient exciton utilization efficiency due to aggregation-caused quenching (ACQ) and intrinsically long triplet exciton lifetimes. To address these limitations, we developed a series of through-space charge transfer (TSCT) TADF sensitizers, which exhibit a minimal singlet-triplet energy gap of 0.06 eV and a rapid reverse intersystem crossing rate (<em>k</em><sub>RISC</sub>) of 3.8 × 10<sup>5</sup> s<sup>−1</sup>. By employing these TSCT-TADF sensitizers in MR-TADF systems to recycle triplet excitons, the resulting TADF-sensitized fluorescent OLED (TSF-OLED) achieved narrowband green emission with a CIE<sub>y</sub> coordinate of 0.71, a maximum external quantum efficiency (EQE<sub>max</sub>) exceeding 35 %, and a suppressed efficiency roll-off of only 26.9 % at 1000 cd m<sup>−2</sup>.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"149 ","pages":"Article 107369"},"PeriodicalIF":2.6,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837154","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}
Organic solar cells with excellent anti-photodegradation property have leaned forward real application. Herein, two benzotriazole-based dimer isomers tethered with octylene linker, namely BN12-C8 and BN22-C8, have been synthesized as solid additives to utilize the ultraviolet (UV) light and then promote the anti-photodegradation capability. Intriguingly, the dimerized solid additive BN22-C8 can improve the photovoltaic performance and photostability of the as-cast device based on PM6:Y6 simultaneously. Furthermore, the temperature-dependent absorption method of blend films revealed that the increased thermal transition temperature derived from the insertion of BN22-C8 played a vital role on excellent device photostability. Our work demonstrates that solid additive with remarkable UV light harvesting could promote the commercial process of OSCs.
{"title":"Isomerized solid additive yields stable organic solar cells","authors":"Yexin Le , Jiafeng Zhang , Lianjie Zhang, Xing Chen, Junwu Chen","doi":"10.1016/j.orgel.2025.107368","DOIUrl":"10.1016/j.orgel.2025.107368","url":null,"abstract":"<div><div>Organic solar cells with excellent <em>anti</em>-photodegradation property have leaned forward real application. Herein, two benzotriazole-based dimer isomers tethered with octylene linker, namely BN12-C8 and BN22-C8, have been synthesized as solid additives to utilize the ultraviolet (UV) light and then promote the <em>anti</em>-photodegradation capability. Intriguingly, the dimerized solid additive BN22-C8 can improve the photovoltaic performance and photostability of the as-cast device based on PM6:Y6 simultaneously. Furthermore, the temperature-dependent absorption method of blend films revealed that the increased thermal transition temperature derived from the insertion of BN22-C8 played a vital role on excellent device photostability. Our work demonstrates that solid additive with remarkable UV light harvesting could promote the commercial process of OSCs.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"149 ","pages":"Article 107368"},"PeriodicalIF":2.6,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837155","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}
Pub Date : 2025-12-16DOI: 10.1016/j.orgel.2025.107367
Heyi Zhang , Juan Bisquert
Organic electrochemical transistors (OECTs) exhibit transient current responses governed by the interplay between ionic motion and electronic transport in the polymer channel. In this work, transient behaviours of PEDOT:PSS OECTs are investigated under a step change in gate voltage. The gate current consistently decays exponentially across different drain biases, allowing extraction of the ionic diffusion time constant via comparison with an analytical model. In contrast, drain current transients show bias- and polarity-dependent temporal profiles, reflecting the modulation of lateral transit of electronic carriers by the drain-source potential. Despite these variations, the extracted decay constants remain consistent with those from gate-current analysis. These results demonstrate that vertical ionic diffusion predominantly determines the device's intrinsic temporal response and lateral electronic transport shapes the transient characteristics, providing a clear physical basis for interpreting time-dependent behaviours in mixed ionic–electronic conductors.
{"title":"Gate-voltage-dependent ionic diffusion and transient dynamics in organic electrochemical transistors","authors":"Heyi Zhang , Juan Bisquert","doi":"10.1016/j.orgel.2025.107367","DOIUrl":"10.1016/j.orgel.2025.107367","url":null,"abstract":"<div><div>Organic electrochemical transistors (OECTs) exhibit transient current responses governed by the interplay between ionic motion and electronic transport in the polymer channel. In this work, transient behaviours of PEDOT:PSS OECTs are investigated under a step change in gate voltage. The gate current consistently decays exponentially across different drain biases, allowing extraction of the ionic diffusion time constant <span><math><mrow><msub><mi>τ</mi><mi>d</mi></msub></mrow></math></span> via comparison with an analytical model. In contrast, drain current transients show bias- and polarity-dependent temporal profiles, reflecting the modulation of lateral transit of electronic carriers by the drain-source potential. Despite these variations, the extracted decay constants remain consistent with those from gate-current analysis. These results demonstrate that vertical ionic diffusion predominantly determines the device's intrinsic temporal response and lateral electronic transport shapes the transient characteristics, providing a clear physical basis for interpreting time-dependent behaviours in mixed ionic–electronic conductors.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"149 ","pages":"Article 107367"},"PeriodicalIF":2.6,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788314","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}
Two-terminal memristors exhibiting voltage-induced resistive switching have emerged as potential device for neuromorphic computing. The simple device architecture with crossbar array pattern of such device is ideal for implementing various synaptic functions and adaptive learning. Herein, we have successfully fabricated organic memristor devices by utilizing self-assembled crystalline thin film of 7,7,8,8-tetracyanoquinodimethane (TCNQ) in ITO/TCNQ/Al configuration. The device exhibited reproducible resistive switching at bias < ± 3V with current On/Off ratio ∼103 and switching time <2 ns. The memory retention characteristics of the device exceeded 103 cycles with stable switching performances. Analysis of the charge transport mechanism of the device via fitting of I–V characteristics using established conduction models confirmed that trap-controlled space-charge limited current (SCLC) governs the switching behavior and underpins the bistable performance of the memory device. The devices demonstrate great promise for use as artificial synapses and in low-energy neuromorphic computation applications. Various biological synaptic functions, such as, LTP, LTD, PPF, SVDP, STDP and EPSC have been successfully emulated using this artificial synaptic device with energy consumption of 197 nJ.
{"title":"Two terminal artificial synaptic devices from self-assembled, crystalline thin film of an organic small molecule for neuromorphic applications","authors":"Nayan Pandit, Rajkumar Mandal, Ankita Pal, Arka Mandal, Rajib Nath, Biswanath Mukherjee","doi":"10.1016/j.orgel.2025.107364","DOIUrl":"10.1016/j.orgel.2025.107364","url":null,"abstract":"<div><div>Two-terminal memristors exhibiting voltage-induced resistive switching have emerged as potential device for neuromorphic computing. The simple device architecture with crossbar array pattern of such device is ideal for implementing various synaptic functions and adaptive learning. Herein, we have successfully fabricated organic memristor devices by utilizing self-assembled crystalline thin film of <em>7,7,8,8-</em>tetracyanoquinodimethane (TCNQ) in ITO/TCNQ/Al configuration. The device exhibited reproducible resistive switching at bias < ± 3V with current On/Off ratio ∼10<sup>3</sup> and switching time <2 ns. The memory retention characteristics of the device exceeded 10<sup>3</sup> cycles with stable switching performances. Analysis of the charge transport mechanism of the device via fitting of <em>I–V</em> characteristics using established conduction models confirmed that trap-controlled space-charge limited current (SCLC) governs the switching behavior and underpins the bistable performance of the memory device. The devices demonstrate great promise for use as artificial synapses and in low-energy neuromorphic computation applications. Various biological synaptic functions, such as, LTP, LTD, PPF, SVDP, STDP and EPSC have been successfully emulated using this artificial synaptic device with energy consumption of 197 nJ.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"149 ","pages":"Article 107364"},"PeriodicalIF":2.6,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145665539","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}
Pub Date : 2025-11-24DOI: 10.1016/j.orgel.2025.107359
Jinan Tang , Bichen Wang , Renyin Zhou , Baoping Lin , Yueming Sun , Guimin Zhao
Blue constitutes one of the three primary colors essential for full-color emission, rendering efficient and stable blue emitters indispensable for high-color-purity organic light-emitting diodes (OLEDs). Aza-boron-diquinomethene (aza-BODIQU) complexes are known to exhibit exceptionally narrow 0-0 emission as high-performance blue fluorescent emitters; however, their color purity is compromised by prominent 0–1 vibronic peaks. Herein, three aza-BODIQU derivatives Ph-BF, 3Ph-BF, and 4Ph-BF are designed to achieve narrowband emission by incorporating non-emissive steric hindrance groups, which effectively attenuate emission sideband and mitigate aggregation-induced spectral redshift and broadening. In solution, these emitters deliver emission peaks at 462, 463, 461 nm with full widths at half maximum (FWHM) as narrow as 12 nm and photoluminescence quantum yields (PLQYs) of 0.91, 0.92 and 0.94. In both non-sensitized and sensitized doped films, progressively bulkier substituents enhance resistance to concentration quenching, yielding markedly reduced redshifts at elevated doping concentrations. Leveraging dendritic thermally activated delayed fluorescence (TADF) sensitization, the resulting devices exhibit narrowband electroluminescence. With increasing steric bulk of the modifying groups, electroluminescence FWHM progressively narrows to 50, 46, and 22 nm, respectively. Correspondingly, maximum external quantum efficiencies (EQEmax) reach 0.7 %, 1.8 %, and 2.1 %, accompanied by peak power efficiencies of 0.7, 2.4, and 2.8 lm W−1 and current efficiencies of 2.2, 5.8, and 6.8 cd A−1.
蓝色是全彩发光所必需的三原色之一，高色纯度有机发光二极管（oled）必不可少的高效、稳定的蓝色发光体。已知aza-硼-二醌配合物（aza-BODIQU）作为高性能蓝色荧光发射器具有异常窄的0-0发射；然而，它们的颜色纯度受到明显的0-1振动峰的影响。本文设计了三种aza-BODIQU衍生物Ph-BF、3Ph-BF和4Ph-BF，通过加入非发射位阻基团实现窄带发射，有效地衰减了发射边带，减轻了聚集引起的光谱红移和展宽。在溶液中，这些发射体在462,463,461 nm处发射峰，半峰全宽（FWHM）窄至12 nm，光致发光量子产率（PLQYs）分别为0.91,0.92和0.94。在非敏化和敏化掺杂薄膜中，体积逐渐增大的取代基增强了对浓度猝灭的抵抗力，在高掺杂浓度下产生明显减少的红移。利用树突热激活延迟荧光（TADF）敏化，所得器件表现出窄带电致发光。随着修饰基团空间体积的增加，电致发光FWHM分别逐渐缩小到50、46和22 nm。相应地，最大外部量子效率（EQEmax）达到0.7%，1.8%和2.1%，峰值功率效率为0.7,2.4和2.8 lm W−1，电流效率为2.2,5.8和6.8 cd A−1。
{"title":"Blue narrowband emission in aza-boron-diquinomethene complexes via steric engineering to reduce vibronic shoulder","authors":"Jinan Tang , Bichen Wang , Renyin Zhou , Baoping Lin , Yueming Sun , Guimin Zhao","doi":"10.1016/j.orgel.2025.107359","DOIUrl":"10.1016/j.orgel.2025.107359","url":null,"abstract":"<div><div>Blue constitutes one of the three primary colors essential for full-color emission, rendering efficient and stable blue emitters indispensable for high-color-purity organic light-emitting diodes (OLEDs). Aza-boron-diquinomethene (aza-BODIQU) complexes are known to exhibit exceptionally narrow 0-0 emission as high-performance blue fluorescent emitters; however, their color purity is compromised by prominent 0–1 vibronic peaks. Herein, three aza-BODIQU derivatives Ph-BF, 3Ph-BF, and 4Ph-BF are designed to achieve narrowband emission by incorporating non-emissive steric hindrance groups, which effectively attenuate emission sideband and mitigate aggregation-induced spectral redshift and broadening. In solution, these emitters deliver emission peaks at 462, 463, 461 nm with full widths at half maximum (FWHM) as narrow as 12 nm and photoluminescence quantum yields (PLQYs) of 0.91, 0.92 and 0.94. In both non-sensitized and sensitized doped films, progressively bulkier substituents enhance resistance to concentration quenching, yielding markedly reduced redshifts at elevated doping concentrations. Leveraging dendritic thermally activated delayed fluorescence (TADF) sensitization, the resulting devices exhibit narrowband electroluminescence. With increasing steric bulk of the modifying groups, electroluminescence FWHM progressively narrows to 50, 46, and 22 nm, respectively. Correspondingly, maximum external quantum efficiencies (EQE<sub>max</sub>) reach 0.7 %, 1.8 %, and 2.1 %, accompanied by peak power efficiencies of 0.7, 2.4, and 2.8 lm W<sup>−1</sup> and current efficiencies of 2.2, 5.8, and 6.8 cd A<sup>−1</sup>.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"148 ","pages":"Article 107359"},"PeriodicalIF":2.6,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620211","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}
Pub Date : 2025-11-21DOI: 10.1016/j.orgel.2025.107358
Xiaolu Chen , Yidong Zhao , Zihe Cao , Youqian Sun , Wenming Zhang , Yi Yang , Bing Zhang , Ji Liu , Zhenxi Zhang , Qiang Lu
Perovskite materials exhibit significant potential in optoelectronic applications, with system energy and band gap serving as critical metrics for evaluating material stability and optical characteristics. To accelerate the development of high-performance perovskite materials, this study establishes an efficient structure-property prediction framework through machine learning approaches. Artificial neural network (ANN) potential models and random forest (RF) models were established using Gaussian-type structure descriptors (GTSD) and power-type structural descriptors (PTSD) as feature inputs, based on a comprehensive dataset of 1000 FAPbI3 configurations with corresponding system energies and band gap values. The RF-based feature selection method was subsequently employed to identify key structural descriptors governing the energy landscape and electronic properties of FAPbI3. Furthermore, the predictive robustness of neural networks across datasets with varying structural perturbations was systematically investigated, revealing critical insights into model generalization capabilities. This computational framework demonstrates high-precision prediction of structure-property relationships while providing mechanistic interpretation of dominant structural factors, thereby offering valuable guidance for rational design of perovskite materials.
{"title":"Machine learning-driven prediction of energy and band gap in FAPbI3 perovskite using diverse structural descriptors","authors":"Xiaolu Chen , Yidong Zhao , Zihe Cao , Youqian Sun , Wenming Zhang , Yi Yang , Bing Zhang , Ji Liu , Zhenxi Zhang , Qiang Lu","doi":"10.1016/j.orgel.2025.107358","DOIUrl":"10.1016/j.orgel.2025.107358","url":null,"abstract":"<div><div>Perovskite materials exhibit significant potential in optoelectronic applications, with system energy and band gap serving as critical metrics for evaluating material stability and optical characteristics. To accelerate the development of high-performance perovskite materials, this study establishes an efficient structure-property prediction framework through machine learning approaches. Artificial neural network (ANN) potential models and random forest (RF) models were established using Gaussian-type structure descriptors (GTSD) and power-type structural descriptors (PTSD) as feature inputs, based on a comprehensive dataset of 1000 FAPbI<sub>3</sub> configurations with corresponding system energies and band gap values. The RF-based feature selection method was subsequently employed to identify key structural descriptors governing the energy landscape and electronic properties of FAPbI<sub>3</sub>. Furthermore, the predictive robustness of neural networks across datasets with varying structural perturbations was systematically investigated, revealing critical insights into model generalization capabilities. This computational framework demonstrates high-precision prediction of structure-property relationships while providing mechanistic interpretation of dominant structural factors, thereby offering valuable guidance for rational design of perovskite materials.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"148 ","pages":"Article 107358"},"PeriodicalIF":2.6,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620210","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}
Pub Date : 2025-11-11DOI: 10.1016/j.orgel.2025.107356
José Carlos Pérez-Martínez, Diego Martín-Martín, Belén Arredondo, Beatriz Romero
Perovskite-based memristors have emerged as promising devices for information storage and processing due to their resistive switching properties. In this study, nonvolatile resistive switching memory devices based on metal halide perovskite with structure FTO/methylammonium lead iodide (MAPbI3)/polymethyl methacrylate (PMMA)/Ag are presented. The influence of buffer layer thickness (PMMA) variations at 30 nm, 50 nm, and 70 nm on device performance is evaluated. Experimental results show that key device parameters such as SET voltage, ON/OFF ratio, endurance and retention time are significantly affected by changes in the buffer layer thickness. Our findings show that an optimum thickness of 50 nm improves the stability and performance of the device, with ultra-high ON/OFF ratios (106), record endurances (>3·104 cycles) and a record retention time (>5·105 s). AC characterization has also been carried out to gain a deeper understanding of the physical mechanisms governing the device. Finally, numerical simulations are carried out to understand the role of the electric field in the formation and rupture of conductive filaments within both the perovskite and buffer layers in devices with different buffer layer thicknesses.
{"title":"Impact of buffer layer thickness on the performance of metal halide perovskite memristors","authors":"José Carlos Pérez-Martínez, Diego Martín-Martín, Belén Arredondo, Beatriz Romero","doi":"10.1016/j.orgel.2025.107356","DOIUrl":"10.1016/j.orgel.2025.107356","url":null,"abstract":"<div><div>Perovskite-based memristors have emerged as promising devices for information storage and processing due to their resistive switching properties. In this study, nonvolatile resistive switching memory devices based on metal halide perovskite with structure FTO/methylammonium lead iodide (MAPbI<sub>3</sub>)/polymethyl methacrylate (PMMA)/Ag are presented. The influence of buffer layer thickness (PMMA) variations at 30 nm, 50 nm, and 70 nm on device performance is evaluated. Experimental results show that key device parameters such as SET voltage, ON/OFF ratio, endurance and retention time are significantly affected by changes in the buffer layer thickness. Our findings show that an optimum thickness of 50 nm improves the stability and performance of the device, with ultra-high ON/OFF ratios (10<sup>6</sup>), record endurances (>3·10<sup>4</sup> cycles) and a record retention time (>5·10<sup>5</sup> s). AC characterization has also been carried out to gain a deeper understanding of the physical mechanisms governing the device. Finally, numerical simulations are carried out to understand the role of the electric field in the formation and rupture of conductive filaments within both the perovskite and buffer layers in devices with different buffer layer thicknesses.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"148 ","pages":"Article 107356"},"PeriodicalIF":2.6,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526025","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}
Pub Date : 2025-11-10DOI: 10.1016/j.orgel.2025.107357
Qian Li , Zeyu Yin , Sen Chen , Qingyan Hou , Pan Pang , Yifan Zhang , Shouzheng Jiao , Lin Chen
Encapsulation is crucial for protecting organic light-emitting diodes (OLEDs) from the effects of water vapor and oxygen in the air, and extending their lifespan. This study reports the use of TiO2 films grown based on filtering cathode vacuum arc (FCVA) technology for flexible OLED device packaging. To ensure the bending service life of flexible OLED devices, high pulse bias is applied, and low stress, high density TiO2 thin films are prepared at room temperature through a deposition mode of short-term high-energy ion bombardment and long-term relaxation. The results showed that the stress of the film significantly decreased to −89 MPa after applying a bias voltage. Under the conditions of 85 °C and 85 % relative humidity, the water vapor transmission rate (WVTR) of TiO2/PEN samples prepared under 7 kV negative bias was 6.23 × 10−3 g/m2/day after bending experiment, which was two order of magnitude lower than the samples prepared without negative bias. In addition, brightness tests on packaged devices have shown that OLED devices packaged with TiO2 films have an extended lifespan of approximately 0.8 times.
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Pub Date : 2025-11-03DOI: 10.1016/j.orgel.2025.107355
Jinming Li , Yangkai Zhao , Linyi Song , Yujian Liu , Xuankang Zhang , Baoxiu Mi , Qi Wei , Quli Fan , Yan Qian
Traditional white organic light-emitting diodes (WOLEDs) often rely on mechanism of incomplete energy transfer, which generally necessitate extremely low doping concentrations for low-energy emitters. This poses significant challenges in device fabrication reproducibility and color coordinate consistency. In this work, we developed a hot exciton yellow-emitting excited state intramolecular proton transfer (ESIPT) fluorophore, T4AC, featuring a large Stokes shift. The material achieves a high exciton utilization efficiency of up to 88.8 %, via high-energy-level reverse intersystem crossing (hRISC). By co-doping T4AC with a thermally activated delayed fluorescence (TADF) blue emitter, DMAc-MPM, we realized highly efficient and reproducible bluish WOLEDs employing a single emitting layer with complementary-color emissions. Minimal spectral overlap effectively suppressed energy transfer, thus ensuring independent triplet harvesting via hot exciton mechanism in T4AC and the TADF process in DMAc-MPM, respectively. The resulting device exhibits color stable and high-efficiency cold white emission, achieving maximum external quantum efficiency (EQE) of 11.50 % and current efficiency (CE) of 27.74 cd A−1. More importantly, these bluish WOLEDs demonstrated excellent reproducibility across multiple batches, with small EQE variations within 11.15 % ± 0.62 % and CIE coordinate fluctuations confined to a narrow range of (0.181 ± 0.004, 0.351 ± 0.030). This study presents a viable strategy for the development of simple-structured, highly efficient, and reproducibly fabricated cold WOLEDs.
传统的白光有机发光二极管（WOLEDs）通常依赖于不完全能量转移机制，这通常需要极低的掺杂浓度来实现低能发射体。这对器件制造的再现性和颜色坐标一致性提出了重大挑战。在这项工作中，我们开发了一种热激子黄色发射激发态分子内质子转移（ESIPT）荧光团，T4AC，具有大的斯托克斯位移。该材料通过高能反向系统间交叉（hRISC）实现了高达88.8%的激子利用效率。通过将T4AC与热激活延迟荧光（TADF）蓝色发射器DMAc-MPM共掺杂，我们实现了具有互补色发射的单发射层高效可重复的蓝色WOLEDs。最小的光谱重叠有效地抑制了能量转移，从而保证了T4AC中的热激子机制和DMAc-MPM中的TADF过程分别通过独立的三重态收获。该器件具有色稳定、高效的冷白光发射特性，最大外量子效率（EQE）为11.50%，电流效率（CE）为27.74 cd A−1。更重要的是，这些带蓝色的WOLEDs在多个批次中具有出色的再现性，EQE变化在11.15%±0.62%以内，CIE坐标波动在0.181±0.004,0.351±0.030的狭窄范围内。本研究为开发结构简单、高效、可重复制造的冷WOLEDs提供了一种可行的策略。
{"title":"Reproducible high-efficiency and color stable single-emitting-layer cold WOLEDs based on inhibition of energy transfer and efficient exciton harvesting","authors":"Jinming Li , Yangkai Zhao , Linyi Song , Yujian Liu , Xuankang Zhang , Baoxiu Mi , Qi Wei , Quli Fan , Yan Qian","doi":"10.1016/j.orgel.2025.107355","DOIUrl":"10.1016/j.orgel.2025.107355","url":null,"abstract":"<div><div>Traditional white organic light-emitting diodes (WOLEDs) often rely on mechanism of incomplete energy transfer, which generally necessitate extremely low doping concentrations for low-energy emitters. This poses significant challenges in device fabrication reproducibility and color coordinate consistency. In this work, we developed a hot exciton yellow-emitting excited state intramolecular proton transfer (ESIPT) fluorophore, T4AC, featuring a large Stokes shift. The material achieves a high exciton utilization efficiency of up to 88.8 %, via high-energy-level reverse intersystem crossing (hRISC). By co-doping T4AC with a thermally activated delayed fluorescence (TADF) blue emitter, DMAc-MPM, we realized highly efficient and reproducible bluish WOLEDs employing a single emitting layer with complementary-color emissions. Minimal spectral overlap effectively suppressed energy transfer, thus ensuring independent triplet harvesting via hot exciton mechanism in T4AC and the TADF process in DMAc-MPM, respectively. The resulting device exhibits color stable and high-efficiency cold white emission, achieving maximum external quantum efficiency (EQE) of 11.50 % and current efficiency (CE) of 27.74 cd A<sup>−1</sup>. More importantly, these bluish WOLEDs demonstrated excellent reproducibility across multiple batches, with small EQE variations within 11.15 % ± 0.62 % and CIE coordinate fluctuations confined to a narrow range of (0.181 ± 0.004, 0.351 ± 0.030). This study presents a viable strategy for the development of simple-structured, highly efficient, and reproducibly fabricated cold WOLEDs.</div></div>","PeriodicalId":399,"journal":{"name":"Organic Electronics","volume":"148 ","pages":"Article 107355"},"PeriodicalIF":2.6,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463560","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}
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