Pub Date : 2024-10-29DOI: 10.1007/s40843-024-3127-5
Guohui Li (, ), Wenhui Zhao (, ), Kai Lin (, ), Kefan Zhao (, ), Yujing Wang (, ), Aohua Niu (, ), Rong Weng (, ), Kaibo Zheng (, ), Yanxia Cui (, )
Quasi-two dimensional (2D) perovskites have emerged as a promising class of materials due to their remarkable photoluminescence efficiency, which stems from their exceptionally high exciton binding energies. The spatial confinement of excitons within smaller grain sizes could enhance the formation of biexcitons leading to higher radiative recombination efficiency. However, the synthesis of high-quality quasi-2D perovskite thin films with controllable grain sizes remains a challenging task. In this study, we present a facile method for achieving quasi-2D perovskite thin films with controllable grain sizes ranging from 500 to 900 nm. This is accomplished by intermediate phase engineering during the film fabrication process. Our results demonstrate that quasi-2D perovskite films with smaller grain sizes exhibit more efficient bound exciton generation and a reduced stimulated emission threshold down to 15.89 µJ cm−2. Furthermore, femtosecond transient absorption measurements reveal that the decay time of bound excitons is shorter in quasi-2D perovskites with smaller grain sizes compared to that of those with larger grains at the same pump density, which is 230.5 ps. This observation suggests a more efficient exciton recombination process in the smaller grain size regime. Our findings would offer a promising approach for the development of efficient bound exciton lasers.
{"title":"Grain size control in quasi-two-dimensional perovskite thin film via intermediate phase engineering for efficient bound exciton generation","authors":"Guohui Li \u0000 (, ), Wenhui Zhao \u0000 (, ), Kai Lin \u0000 (, ), Kefan Zhao \u0000 (, ), Yujing Wang \u0000 (, ), Aohua Niu \u0000 (, ), Rong Weng \u0000 (, ), Kaibo Zheng \u0000 (, ), Yanxia Cui \u0000 (, )","doi":"10.1007/s40843-024-3127-5","DOIUrl":"10.1007/s40843-024-3127-5","url":null,"abstract":"<div><p>Quasi-two dimensional (2D) perovskites have emerged as a promising class of materials due to their remarkable photoluminescence efficiency, which stems from their exceptionally high exciton binding energies. The spatial confinement of excitons within smaller grain sizes could enhance the formation of biexcitons leading to higher radiative recombination efficiency. However, the synthesis of high-quality quasi-2D perovskite thin films with controllable grain sizes remains a challenging task. In this study, we present a facile method for achieving quasi-2D perovskite thin films with controllable grain sizes ranging from 500 to 900 nm. This is accomplished by intermediate phase engineering during the film fabrication process. Our results demonstrate that quasi-2D perovskite films with smaller grain sizes exhibit more efficient bound exciton generation and a reduced stimulated emission threshold down to 15.89 µJ cm<sup>−2</sup>. Furthermore, femtosecond transient absorption measurements reveal that the decay time of bound excitons is shorter in quasi-2D perovskites with smaller grain sizes compared to that of those with larger grains at the same pump density, which is 230.5 ps. This observation suggests a more efficient exciton recombination process in the smaller grain size regime. Our findings would offer a promising approach for the development of efficient bound exciton lasers.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"67 12","pages":"3925 - 3931"},"PeriodicalIF":6.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40843-024-3127-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1007/s40843-024-3161-x
Ziyue Zeng, Chenyang Wang, Lei Fu
{"title":"Liquid metal catalyst for ammonia synthesis at low pressure","authors":"Ziyue Zeng, Chenyang Wang, Lei Fu","doi":"10.1007/s40843-024-3161-x","DOIUrl":"10.1007/s40843-024-3161-x","url":null,"abstract":"","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"68 2","pages":"681 - 682"},"PeriodicalIF":6.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143110150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of highly efficient and low-cost photocatalysts for degradation of organic pollutants become an effective approach for environmental remediation. However, the practical application of traditional powder catalyst in photocatalytic technology is limited due to its low recycling capacity, agglomeration and secondary pollution risk. Herein, a floating Fe-doped TiO2 and hydrogel (FTH) composite was synthesized for the photodegradation of Rhodamine B via a facile impregnation method. The photodegradation results show that the FTH composite exhibits a higher photocatalytic efficiency with degradation percentage (95.6%) compared with pure TiO2 (41.2%). The enhanced photocatalytic performance is attributed to its excellent flotation performance, providing a large number of active sites for pollutant degradation, contact with O2 and photons at the air/water interface. Remarkably, the adsorbed Rhodamine B in FTH can still be removed by exposing to light in the air alone, demonstrating strong recovery ability of the FIH composite catalyst. The floatable hydrogel nanocomposites offer a promising solution for scalable solar-drive degradation of water pollutants, paving the way for sustainable water treatment technologies.
开发高效、低成本的光催化剂来降解有机污染物已成为一种有效的环境修复方法。然而,由于传统粉末催化剂的回收能力低、团聚和二次污染风险等问题,其在光催化技术中的实际应用受到了限制。本文通过简便的浸渍法合成了一种漂浮的掺铁 TiO2 和水凝胶(FTH)复合材料,用于罗丹明 B 的光降解。光降解结果表明,与纯 TiO2(41.2%)相比,FTH 复合材料具有更高的光催化效率和降解率(95.6%)。光催化性能的提高归功于其出色的浮选性能,为污染物降解提供了大量的活性位点,并在空气/水界面与氧气和光子接触。值得注意的是,FTH 中吸附的罗丹明 B 仍然可以仅通过在空气中暴露于光而被去除,这表明 FIH 复合催化剂具有很强的回收能力。可浮水凝胶纳米复合材料为可扩展的太阳能驱动水污染物降解提供了一种前景广阔的解决方案,为可持续水处理技术铺平了道路。
{"title":"Floatable Fe-TiO2/hydrogel composite for photodegradation of water pollutants","authors":"Ying-Ying Jiao \u0000 (, ), Zhi-Yong Cheng \u0000 (, ), Hao Luo \u0000 (, ), Qiu-Ping Zhao \u0000 (, ), Xue-Yan Xiang \u0000 (, ), Zhi-Ming Zhang \u0000 (, )","doi":"10.1007/s40843-024-3150-2","DOIUrl":"10.1007/s40843-024-3150-2","url":null,"abstract":"<div><p>The development of highly efficient and low-cost photocatalysts for degradation of organic pollutants become an effective approach for environmental remediation. However, the practical application of traditional powder catalyst in photocatalytic technology is limited due to its low recycling capacity, agglomeration and secondary pollution risk. Herein, a floating Fe-doped TiO<sub>2</sub> and hydrogel (FTH) composite was synthesized for the photodegradation of Rhodamine B via a facile impregnation method. The photodegradation results show that the FTH composite exhibits a higher photocatalytic efficiency with degradation percentage (95.6%) compared with pure TiO<sub>2</sub> (41.2%). The enhanced photocatalytic performance is attributed to its excellent flotation performance, providing a large number of active sites for pollutant degradation, contact with O<sub>2</sub> and photons at the air/water interface. Remarkably, the adsorbed Rhodamine B in FTH can still be removed by exposing to light in the air alone, demonstrating strong recovery ability of the FIH composite catalyst. The floatable hydrogel nanocomposites offer a promising solution for scalable solar-drive degradation of water pollutants, paving the way for sustainable water treatment technologies.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"67 12","pages":"4013 - 4020"},"PeriodicalIF":6.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1007/s40843-024-3126-1
Mengtian Huo (, ), Jianhang Sun (, ), Wei Liu (, ), Qianyu Li (, ), Jinfa Chang (, ), Zihao Xing (, )
Sulfur and nitrogen dual-doped graphdiyne (NSGD) has been found to be a promising catalyst for oxygen reduction reaction (ORR) through a combination of density functional theory (DFT) calculation and the application of oxygen evolution reaction (OER) experiments. The DFT analysis suggests that adsorption characteristics are significantly altered by resulting nitrogen and sulfur doping, which in turn affect the ORR activity. In particular, the NSGD-800 catalyst exhibits an increased ORR half-wave potential of 0.754 V, with enhanced stability due to the synergy effect of N and S. Meanwhile, thanks to the unique acetylene-rich structure of graphdiyne to anchor metal oxides with strong d-π interactions, the activity and stability of com-RuO2 for OER were significantly enhanced by mixing with NSGD-800. The zinc-air battery (ZAB) with NSGD shows a much higher peak power density (87.3 mW cm−2) and longer charge-discharge cycle stability compared with the ZAB with Pt/C, making it an excellent candidate air electrode for ZAB and other energy storage and conversion devices.
{"title":"Sulfur and nitrogen dual-doped graphdiyne as a highly efficient metal-free electrocatalyst for the Zn-air battery","authors":"Mengtian Huo \u0000 (, ), Jianhang Sun \u0000 (, ), Wei Liu \u0000 (, ), Qianyu Li \u0000 (, ), Jinfa Chang \u0000 (, ), Zihao Xing \u0000 (, )","doi":"10.1007/s40843-024-3126-1","DOIUrl":"10.1007/s40843-024-3126-1","url":null,"abstract":"<div><p>Sulfur and nitrogen dual-doped graphdiyne (NSGD) has been found to be a promising catalyst for oxygen reduction reaction (ORR) through a combination of density functional theory (DFT) calculation and the application of oxygen evolution reaction (OER) experiments. The DFT analysis suggests that adsorption characteristics are significantly altered by resulting nitrogen and sulfur doping, which in turn affect the ORR activity. In particular, the NSGD-800 catalyst exhibits an increased ORR half-wave potential of 0.754 V, with enhanced stability due to the synergy effect of N and S. Meanwhile, thanks to the unique acetylene-rich structure of graphdiyne to anchor metal oxides with strong d-<i>π</i> interactions, the activity and stability of com-RuO<sub>2</sub> for OER were significantly enhanced by mixing with NSGD-800. The zinc-air battery (ZAB) with NSGD shows a much higher peak power density (87.3 mW cm<sup>−2</sup>) and longer charge-discharge cycle stability compared with the ZAB with Pt/C, making it an excellent candidate air electrode for ZAB and other energy storage and conversion devices.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"67 12","pages":"4005 - 4012"},"PeriodicalIF":6.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1007/s40843-024-3137-4
Bowen Hu (, ), Yanyun Pang (, ), Xiaoxue Yang (, ), Kun Xuan (, ), Xu Zhang (, ), Peng Yang (, )
Dental hard tissues, primarily enamel and dentin, serving essential functions such as cutting, chewing, speaking, and maintaining facial aesthetics, mainly composed well-aligned hydroxyapatite (HAp) nanocrystals interlaced with a protein matrix. These tissues exhibit remarkable mechanical and aesthetic behaviors. However, once damaged, its ability to self-repair is extremely limited, often accompanied by dentin hypersensitivity (DH). Currently, although dental restorations using synthetic materials and remineralization techniques have made clinical progress, these methods still have limitations that affect their widespread use in clinical applications. Therefore, understanding the formation mechanisms of dental hard tissues and developing high-performance restorative technologies that can mimic natural teeth and meet clinical needs are crucial. This review focuses on the current strategies and research advancements in enamel regeneration and dentin desensitization, and challenges of clinical translation. We emphasize that scientific research should start with clinical needs, and these studies, through translation, ultimately serve the clinic to form a mutually reinforcing virtuous cycle. This review aims to provide a new perspective on the prevention and treatment of dental hard tissues, promote innovation in restorative materials and techniques, and bring better clinical translation products and services to patients.
{"title":"Advancements in dental hard tissue restorative materials and challenge of clinical translation","authors":"Bowen Hu \u0000 (, ), Yanyun Pang \u0000 (, ), Xiaoxue Yang \u0000 (, ), Kun Xuan \u0000 (, ), Xu Zhang \u0000 (, ), Peng Yang \u0000 (, )","doi":"10.1007/s40843-024-3137-4","DOIUrl":"10.1007/s40843-024-3137-4","url":null,"abstract":"<div><p>Dental hard tissues, primarily enamel and dentin, serving essential functions such as cutting, chewing, speaking, and maintaining facial aesthetics, mainly composed well-aligned hydroxyapatite (HAp) nanocrystals interlaced with a protein matrix. These tissues exhibit remarkable mechanical and aesthetic behaviors. However, once damaged, its ability to self-repair is extremely limited, often accompanied by dentin hypersensitivity (DH). Currently, although dental restorations using synthetic materials and remineralization techniques have made clinical progress, these methods still have limitations that affect their widespread use in clinical applications. Therefore, understanding the formation mechanisms of dental hard tissues and developing high-performance restorative technologies that can mimic natural teeth and meet clinical needs are crucial. This review focuses on the current strategies and research advancements in enamel regeneration and dentin desensitization, and challenges of clinical translation. We emphasize that scientific research should start with clinical needs, and these studies, through translation, ultimately serve the clinic to form a mutually reinforcing virtuous cycle. This review aims to provide a new perspective on the prevention and treatment of dental hard tissues, promote innovation in restorative materials and techniques, and bring better clinical translation products and services to patients.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"67 12","pages":"3811 - 3832"},"PeriodicalIF":6.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbon molecular sieve membranes (CMSMs) are a class of porous membranes inherited with excellent thermal stability, high tolerance and superior mechanical strength. Owing to their nanoporous structures, CMSMs usually hold significant potential for gas separation applications. Specifically, hyper-crosslinked ionic polymer (HIP) membranes possess a highly crosslinked nitrogen-rich framework, high thermal stability together with exceptional mechanical strength, making them excellent precursors for the CMSMs fabrication. Upon pyrolysis of HIP membranes, the resulting CMSMs featured with nitrogen functional sites exhibit strong interactions with CO2, which significantly reduces the CO2 permeability while other gas molecules continue to flow through the nanoporous membrane. The resultant CMSMs exhibited excellent H2/CO2 selectivity with values of 10.75 and 7.09, together with ultra-high H2 permeability of 3052 and 9181 barrer, respectively, surpassing the Robeson upper bound. The preparation route towards CMSMs with high nitrogen content from HIP can significantly enrich the rational design and synthesis strategies of high-performance gas separation CMSM materials.
{"title":"Ultramicroporous carbon molecular sieve membrane derived from hyper-crosslinked ionic polymers for efficient H2/CO2 separation","authors":"Jiaao Yao \u0000 (, ), Jingjie Bi \u0000 (, ), Hongyu Zuo \u0000 (, ), Yuren Peng \u0000 (, ), Liwei Wu \u0000 (, ), Zixuan Zhang \u0000 (, ), Xuelong He \u0000 (, ), Baokang Lyu \u0000 (, ), Nanwen Li \u0000 (, ), Yaozu Liao \u0000 (, ), Weiyi Zhang \u0000 (, )","doi":"10.1007/s40843-024-3133-1","DOIUrl":"10.1007/s40843-024-3133-1","url":null,"abstract":"<div><p>Carbon molecular sieve membranes (CMSMs) are a class of porous membranes inherited with excellent thermal stability, high tolerance and superior mechanical strength. Owing to their nanoporous structures, CMSMs usually hold significant potential for gas separation applications. Specifically, hyper-crosslinked ionic polymer (HIP) membranes possess a highly crosslinked nitrogen-rich framework, high thermal stability together with exceptional mechanical strength, making them excellent precursors for the CMSMs fabrication. Upon pyrolysis of HIP membranes, the resulting CMSMs featured with nitrogen functional sites exhibit strong interactions with CO<sub>2</sub>, which significantly reduces the CO<sub>2</sub> permeability while other gas molecules continue to flow through the nanoporous membrane. The resultant CMSMs exhibited excellent H<sub>2</sub>/CO<sub>2</sub> selectivity with values of 10.75 and 7.09, together with ultra-high H<sub>2</sub> permeability of 3052 and 9181 barrer, respectively, surpassing the Robeson upper bound. The preparation route towards CMSMs with high nitrogen content from HIP can significantly enrich the rational design and synthesis strategies of high-performance gas separation CMSM materials.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"68 3","pages":"888 - 896"},"PeriodicalIF":6.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-25DOI: 10.1007/s40843-024-3128-5
Da Liu (, ), Jingjing He (, ), Yuting Sun (, ), Xinyi Liu (, ), Yu Peng (, ), Qing Li (, ), Hua Gui Yang (, ), Qiang Niu (, ), Shuang Yang (, ), Yu Hou (, )
Zero-dimensional perovskite materials, characterized by broadband emission caused by self-trapped excitons, are promising materials for stimuli-responsive and photo-writeable encryption. However, existing research is focused on the effects of structural phase transitions on photophysical properties, and lacks in-depth understanding of the mechanisms of self-trapped excitons emission. Here, we demonstrate that the dehydration reaction in zero-dimensional antimony halide clusters significantly enhances the self-trapped excitons emission without inducing structural phase transition, resulting in a substantial increase in photoluminescence (PL) quantum yield from 3.5% to 91.4%. In-situ X-ray diffraction and PL techniques were employed to shed light on the relationship between the crystal structure and radiative recombination, demonstrating the introduction of rich lattice distortion during the dehydration process. Temperature-dependent PL spectra and transient absorption spectra suggest that the lattice distortion causes the moderate electron-phonon coupling strength and high exciton binding energy, facilitating self-trapped excitons to relax from the non-radiative recombination singlet state to the radiative recombination triplet state, corresponding to the enhanced emission intensity. As a proof of concept, several switchable PL applications have been established in scenarios such as anti-counterfeiting, rewritable luminescent paper, and humidity sensing. This finding elucidates the emission mechanism of self-trapped excitons and provides a novel avenue for designing switchable luminescent materials.
{"title":"Lattice distortion enhanced self-trapped excitons emission in antimony halide crystalline clusters","authors":"Da Liu \u0000 (, ), Jingjing He \u0000 (, ), Yuting Sun \u0000 (, ), Xinyi Liu \u0000 (, ), Yu Peng \u0000 (, ), Qing Li \u0000 (, ), Hua Gui Yang \u0000 (, ), Qiang Niu \u0000 (, ), Shuang Yang \u0000 (, ), Yu Hou \u0000 (, )","doi":"10.1007/s40843-024-3128-5","DOIUrl":"10.1007/s40843-024-3128-5","url":null,"abstract":"<div><p>Zero-dimensional perovskite materials, characterized by broadband emission caused by self-trapped excitons, are promising materials for stimuli-responsive and photo-writeable encryption. However, existing research is focused on the effects of structural phase transitions on photophysical properties, and lacks in-depth understanding of the mechanisms of self-trapped excitons emission. Here, we demonstrate that the dehydration reaction in zero-dimensional antimony halide clusters significantly enhances the self-trapped excitons emission without inducing structural phase transition, resulting in a substantial increase in photoluminescence (PL) quantum yield from 3.5% to 91.4%. <i>In-situ</i> X-ray diffraction and PL techniques were employed to shed light on the relationship between the crystal structure and radiative recombination, demonstrating the introduction of rich lattice distortion during the dehydration process. Temperature-dependent PL spectra and transient absorption spectra suggest that the lattice distortion causes the moderate electron-phonon coupling strength and high exciton binding energy, facilitating self-trapped excitons to relax from the non-radiative recombination singlet state to the radiative recombination triplet state, corresponding to the enhanced emission intensity. As a proof of concept, several switchable PL applications have been established in scenarios such as anti-counterfeiting, rewritable luminescent paper, and humidity sensing. This finding elucidates the emission mechanism of self-trapped excitons and provides a novel avenue for designing switchable luminescent materials.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"68 1","pages":"132 - 140"},"PeriodicalIF":6.8,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Signal processing has entered the era of big data, and improving processing efficiency becomes crucial. Traditional computing architectures face computational efficiency limitations due to the separation of storage and computation. Array circuits based on multi-conductor devices enable full hardware convolutional neural networks (CNNs), which hold great potential to improve computational efficiency. However, when processing large-scale convolutional computations, there is still a significant amount of device redundancy, resulting in low computational power consumption and high computational costs. Here, we innovatively propose a memristor-based in-situ convolutional strategy, which uses the dynamic changes in the conductive wire, doping area, and polarization area of memristors as the process of convolutional operations, and uses the time required for conductance switching of a single device as the computation result, embodying convolutional computation through the unique spiked digital signal of the memristor. Our strategy reasonably encodes complex analog signals into simple digital signals through a memristor, completing the convolutional computation at the device level, which is essential for complex signal processing and computational efficiency improvement. Based on the implementation of device-level convolutional computing, we have achieved feature recognition and noise filtering for braille signals. We believe that our successful implementation of convolutional computing at the device level will promote the construction of complex CNNs with large-scale convolutional computing capabilities, bringing innovation and development to the field of neuromorphic computing.
{"title":"Memristor-based in-situ convolutional strategy for accurate braille recognition","authors":"Xianghong Zhang \u0000 (, ), Congyao Qin \u0000 (, ), Wenhong Peng \u0000 (, ), Ningpu Qin \u0000 (, ), Enping Cheng \u0000 (, ), Jianxin Wu \u0000 (, ), Yuyang Fan \u0000 (, ), Qian Yang \u0000 (, ), Huipeng Chen \u0000 (, )","doi":"10.1007/s40843-024-3122-7","DOIUrl":"10.1007/s40843-024-3122-7","url":null,"abstract":"<div><p>Signal processing has entered the era of big data, and improving processing efficiency becomes crucial. Traditional computing architectures face computational efficiency limitations due to the separation of storage and computation. Array circuits based on multi-conductor devices enable full hardware convolutional neural networks (CNNs), which hold great potential to improve computational efficiency. However, when processing large-scale convolutional computations, there is still a significant amount of device redundancy, resulting in low computational power consumption and high computational costs. Here, we innovatively propose a memristor-based <i>in-situ</i> convolutional strategy, which uses the dynamic changes in the conductive wire, doping area, and polarization area of memristors as the process of convolutional operations, and uses the time required for conductance switching of a single device as the computation result, embodying convolutional computation through the unique spiked digital signal of the memristor. Our strategy reasonably encodes complex analog signals into simple digital signals through a memristor, completing the convolutional computation at the device level, which is essential for complex signal processing and computational efficiency improvement. Based on the implementation of device-level convolutional computing, we have achieved feature recognition and noise filtering for braille signals. We believe that our successful implementation of convolutional computing at the device level will promote the construction of complex CNNs with large-scale convolutional computing capabilities, bringing innovation and development to the field of neuromorphic computing.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"67 12","pages":"3986 - 3993"},"PeriodicalIF":6.8,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22DOI: 10.1007/s40843-024-3114-4
Ivan A. Kruglov (, ), Liudmila A. Bereznikova (, ), Congwei Xie (, ), Dongdong Chu (, ), Ke Li (, ), Evgenii Tikhonov (, ), Abudukadi Tudi (, ), Arslan Mazitov (, ), Min Zhang (, ), Shilie Pan (, ), Zhihua Yang (, )
Finding crystals with high birefringence (Δn), especially in deep-ultraviolet (DUV) regions, is important for developing polarization devices such as optical fiber sensors. Such materials are usually discovered using experimental techniques, which are costly and inefficient for a large-scale screening. Herein, we collected a database of crystal structures and their optical properties and trained atomistic line graph neural network to predict their Δn. To estimate the level of confidence of the trained model on new data, D-optimality criterion was implemented. Using trained graph neural network, we searched for novel materials with high Δn in the Materials Project database and discovered two new DUV birefringent candidates: NaYCO3F2 and SClO2F, with high Δn values of 0.202 and 0.101 at 1064 nm, respectively. Further analysis reveals that strongly anisotropic units with various anions and π-conjugated planar groups are beneficial for high Δn.
{"title":"Graph neural network guided design of novel deep-ultraviolet optical materials with high birefringence","authors":"Ivan A. Kruglov \u0000 (, ), Liudmila A. Bereznikova \u0000 (, ), Congwei Xie \u0000 (, ), Dongdong Chu \u0000 (, ), Ke Li \u0000 (, ), Evgenii Tikhonov \u0000 (, ), Abudukadi Tudi \u0000 (, ), Arslan Mazitov \u0000 (, ), Min Zhang \u0000 (, ), Shilie Pan \u0000 (, ), Zhihua Yang \u0000 (, )","doi":"10.1007/s40843-024-3114-4","DOIUrl":"10.1007/s40843-024-3114-4","url":null,"abstract":"<div><p>Finding crystals with high birefringence (Δ<i>n</i>), especially in deep-ultraviolet (DUV) regions, is important for developing polarization devices such as optical fiber sensors. Such materials are usually discovered using experimental techniques, which are costly and inefficient for a large-scale screening. Herein, we collected a database of crystal structures and their optical properties and trained atomistic line graph neural network to predict their Δ<i>n</i>. To estimate the level of confidence of the trained model on new data, D-optimality criterion was implemented. Using trained graph neural network, we searched for novel materials with high Δ<i>n</i> in the Materials Project database and discovered two new DUV birefringent candidates: NaYCO<sub>3</sub>F<sub>2</sub> and SClO<sub>2</sub>F, with high Δ<i>n</i> values of 0.202 and 0.101 at 1064 nm, respectively. Further analysis reveals that strongly anisotropic units with various anions and <i>π</i>-conjugated planar groups are beneficial for high Δ<i>n</i>.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":773,"journal":{"name":"Science China Materials","volume":"67 12","pages":"3941 - 3947"},"PeriodicalIF":6.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}