{"title":"Contact Engineering in Two-Dimensional Transition Metal Dichalcogenide-Based Devices: Industry-Compatible Approaches toward Ultralow Contact Resistance","authors":"Jeongwoo Seo, Inkyu Sohn and Hyungjun Kim*, ","doi":"10.1021/acsmaterialslett.5c01010","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c01010","url":null,"abstract":"<p >The performance of electronic devices is critically governed by the contact properties at metal–semiconductor (MS) junctions, which directly affect the contact resistance (R<sub>c</sub>) and charge transport characteristics. Accordingly, contact engineering has received considerable attention in the semiconductor industry. However, conventional contact engineering approaches designed for bulk semiconductors are not compatible with two-dimensional transition metal dichalcogenides (2D TMDCs) due to their atomically thin structure, thereby presenting challenges to the development of 2D electronic devices. In this Review, various alternative approaches are systematically explored to improve contact properties and reduce R<sub>c</sub> at the metal–2D TMDC junction. We highlight recent progress in industry-compatible contact engineering techniques, especially those involving modifications of contact geometry. By establishing high-quality contact interfaces, these strategies are expected to play a crucial role in advancing the industrial application of next-generation 2D electronic devices in the post-silicon era.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3190–3205"},"PeriodicalIF":8.7,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biqi He, Kuan Kuang, Mingkai Li, Jie Yang, Lei Zhang*, Yunbin He* and Junnian Chen*,
{"title":"Conformational Disorder of Organic Cations Induces Charge Localization in 3D Lead Iodide Perovskitoids toward Sensitive Photodetectors","authors":"Biqi He, Kuan Kuang, Mingkai Li, Jie Yang, Lei Zhang*, Yunbin He* and Junnian Chen*, ","doi":"10.1021/acsmaterialslett.5c00995","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00995","url":null,"abstract":"<p >Three-dimensional (3D) hybrid halide perovskitoids have drawn intense attention in the optoelectronic fields. Therefore, understanding the structural effects on the charge carrier behavior is essential for device optimization. Herein, we establish the correlation between the conformational disorder of cations and the charge carrier property in 3D perovskitoids using computational and experimental investigations. It is shown that the conformational disorder of <i>N,N′</i>-dimethyl-1,3-propane diammonium (M<sub>2</sub>PDA) cations induces great distortion of the [Pb<sub>2</sub>I<sub>10</sub>]<sup>6–</sup> inorganic framework in 3D (M<sub>2</sub>PDA)Pb<sub>2</sub>I<sub>6</sub>, leading to distinct charge localization. Moreover, the cation configuration disorder suppresses defect formation, thereby reducing lattice microstrain. These modifications effectively elongate the carrier lifetime and diminish carrier scattering to facilitate charge carrier transport. As a result, a photodetector assembled from (M<sub>2</sub>PDA)Pb<sub>2</sub>I<sub>6</sub> single crystals achieves a satisfying on/off current ratio of 1.42 × 10<sup>4</sup> and responsivity of 0.55 A W<sup>–1</sup>, ranking among the highest-performing devices based on 3D perovskitoids. Moreover, the (M<sub>2</sub>PDA)Pb<sub>2</sub>I<sub>6</sub> single crystals display superior stability in 100% isopropanol.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3182–3189"},"PeriodicalIF":8.7,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuchao Li, Zhengli Liang, Youquan Liu, Qin Chen, Ran Zhang, Xingxing Jiang*, Martin T. Dove and Zheshuai Lin*,
{"title":"Negative Thermal Expansion in Cuprite-Type M2X (M = Cu, Ag, Au; X = O, S): A Quasi-Harmonic Lattice Dynamics Study","authors":"Yuchao Li, Zhengli Liang, Youquan Liu, Qin Chen, Ran Zhang, Xingxing Jiang*, Martin T. Dove and Zheshuai Lin*, ","doi":"10.1021/acsmaterialslett.5c00793","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00793","url":null,"abstract":"<p >Understanding the mechanisms of negative thermal expansion (NTE) in solids is crucial for controlling this anomalous thermal response. In this work, we investigate NTE in the cuprite-type M<sub>2</sub>X family (M = Cu, Ag, Au; X = O, S) by first-principles quasi-harmonic lattice dynamics simulations. Au<sub>2</sub>S has a much more pronounced NTE effect than Cu<sub>2</sub>O and Ag<sub>2</sub>O in experimentally available structures, while the predicted Cu<sub>2</sub>S exhibits the most pronounced NTE response within this family. Their predicted NTE is dominated by low-frequency optical and transverse phonon modes, which drives the deformation of [XM<sub>4</sub>] tetrahedra, and arises from the competition between transverse and longitudinal vibrations in bridging atoms. Notably, we establish a characteristic ratio of transverse to longitudinal vibration permissibility that shows nearly linear correlation with NTE magnitude across this family. This work clarifies structure–property relationships for NTE in cuprite-type materials and reveals fundamental insights to guide the development of NTE materials.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3174–3181"},"PeriodicalIF":8.7,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ultrasensitive Mechanoluminescence Materials by Controlling Molecular Aggregation State via Different Alkyl Groups","authors":"Richao Shen, Yuqing Sun, Jiawei Lv, Cheng Zeng, Haowen Huang, Sanbao Wang, Shuangyu Dong, Yong Li, Hongting Fan, Ziqiang Lei* and Hengchang Ma*, ","doi":"10.1021/acsmaterialslett.5c00589","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00589","url":null,"abstract":"<p >Organic mechanoluminescence (ML) materials have drawn considerable research attention in the past few years due to their diverse applications in many fields. However, owing to the absence of a rationally designing concept at molecular level, the ML-active organomaterials with ultrasensitivity have been scarcely reported. In this contribution, alkyl groups with different steric hindrances were introduced into triphenylamine (TPA) derivatives’ skeleton, resulting in six compounds as TPA-CHO, MTPA-CHO, ITPA-CHO, sTTPA-CHO, TTPA-CHO, and dTTPA-CHO. Through detailed analysis of their crystal structure and theoretical calculations, it was affirmed that the presence of alkyl groups in TPA derivatives leads to a range of aggregation states, which manage the TPA derivatives with or without ML performance. Contrast to various analogues, TTPA-CHO exhibited bright and the most sensitive ML performance under a mechanical force stimulation of 0.1 N. Based on the ultrasensitive ML characteristic, the applications of information storage and encryption were successfully demonstrated.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3167–3173"},"PeriodicalIF":8.7,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yujie Yang, Xin Chen, Zhenglin Jia, Yong Liu and Qianqian Lin*,
{"title":"Device Engineering of Bismuth-Based Chalcogenides for Low-Noise, Near-Infrared Photon-Counting","authors":"Yujie Yang, Xin Chen, Zhenglin Jia, Yong Liu and Qianqian Lin*, ","doi":"10.1021/acsmaterialslett.5c00864","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00864","url":null,"abstract":"<p >Near-infrared (NIR) photodetection is critical for both military and civilian applications. However, conventional NIR detectors often suffer from high dark currents and reliance on cryogenic cooling, limiting their use in demanding environments. To overcome these challenges, we developed high-quality bismuth-based chalcogenide bilayer films using a cost-effective solution process and fabricated the corresponding photodiodes. The resulting silver bismuth sulfide/antimony bismuth sulfide bilayer photodetectors possess the metrics of both low dark current of antimony bismuth sulfide-based devices and the broad spectral response of silver bismuth sulfide-based photodetectors, exhibiting a synergistic enhancement in performance. The optimized photodiodes achieve an extended detection range up to 1250 nm while demonstrating excellent performance metrics, including ultralow dark current and noise, high sensitivity, fast response and outstanding stability. Moreover, these devices show promising potential for NIR photon-counting and optical communication, offering a viable pathway toward high-performance near-infrared photodetectors working at room temperature.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3159–3166"},"PeriodicalIF":8.7,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yan Luo, Hardik Makkar, Yuntao Hu, Keyu Chen, Prashant K. Purohit and Kyle H. Vining*,
{"title":"Shape Memory Collagen Scaffolds Sustain Large-Scale Cyclic Loading","authors":"Yan Luo, Hardik Makkar, Yuntao Hu, Keyu Chen, Prashant K. Purohit and Kyle H. Vining*, ","doi":"10.1021/acsmaterialslett.5c00817","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00817","url":null,"abstract":"<p >Natural biopolymer hydrogels often suffer from relatively low moduli and an inability to maintain structure and mechanics under cyclic loading, limiting their utility in dynamic mechanical environments. Here, a cross-linked collagen cryogel scaffold was fabricated by precompression to densify the network. Following lyophilization, the porous scaffolds sustained >90% axial compressive strain with 200 cycles. Ogden hyperelastic modeling and second harmonic generation (SHG) imaging revealed fiber alignment, densification, and strain-stiffening contributing to resilience under repetitive large-scale loading. After rehydration, cross-linked and densified hydrogels showed network stability and recoverability under cyclic loading, with significantly reduced phase transition strains compared to non-cross-linked controls. The scaffolds supported cell encapsulation and maintained cell viability after 50 cycles of 90% strain. Cyclic loading significantly densified the encapsulated cells in the loading direction, comparable to nonloaded controls. Overall, these results suggest that densified, shape memory collagen scaffolds provide a mechanically robust and biocompatible system for dynamic environments.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3150–3158"},"PeriodicalIF":8.7,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsmaterialslett.5c00817","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhao Li, Bushra Tousian, Michal Zaiden, Ishani Sarkar, Clark Vu, Yin Wang*, Ronit Bitton* and John B. Matson*,
{"title":"Cellular Uptake and Antioxidant Activity of H2S-Releasing Tetrapeptide Supramolecular Polymer Nanostructures","authors":"Zhao Li, Bushra Tousian, Michal Zaiden, Ishani Sarkar, Clark Vu, Yin Wang*, Ronit Bitton* and John B. Matson*, ","doi":"10.1021/acsmaterialslett.5c00921","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00921","url":null,"abstract":"<p >Self-assembled peptide–H<sub>2</sub>S donor conjugates (PHDCs) can deliver hydrogen sulfide in vitro and in vivo, yet the link between the supramolecular nanostructure morphology and cellular uptake remains unclear. Herein, we designed constitutionally isomeric PHDCs that self-assembled in aqueous solution into either nanoribbons, nanofibers, or nanobelts with various dimensions based on cryogenic transmission electron microscopy and small-angle X-ray scattering. Nile-red loaded PHDCs showed morphology-dependent uptake by H9C2 cells based on fluorescence microscopy combined with flow cytometry and confocal imaging, where narrow, helically twisted nanoribbons entered most efficiently. All PHDCs released H<sub>2</sub>S at similar rates, but the amount of H<sub>2</sub>S released inside the cells depended on the internalization ability of each PHDC. Consistent with these results, the narrow twisted nanoribbons afforded the greatest protection against H<sub>2</sub>O<sub>2</sub>-induced oxidative stress. Overall, this study highlights how subtle molecular-level changes can influence nanostructure formation in supramolecular assemblies and ultimately affect their cellular uptake and biological activities.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3141–3149"},"PeriodicalIF":8.7,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsmaterialslett.5c00921","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strategies for Advancing Electrodeposited Co-Based Oxygen Evolution Catalysts from Alkaline to Pure-Water Conditions","authors":"Sanghwi Han, and , Jeyong Yoon*, ","doi":"10.1021/acsmaterialslett.5c00949","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00949","url":null,"abstract":"<p >Anion exchange membrane water electrolysis (AEMWE) is a promising platform for scalable and cost-effective green hydrogen production. Extensive research efforts have focused on enhancing the oxygen evolution reaction (OER) activity from alkaline to pure-water conditions. Co-based catalysts have shown high activity and stability for OER across alkaline to near-neutral conditions, making them strong candidates for AEMWE. In addition, electrodeposition offers a simple, scalable, and low-cost method for synthesizing these catalysts with tailored properties. Despite numerous advances in enhancing catalytic performance, comprehensive guidance on tailoring these catalysts to different electrolyte environments remains limited. This study suggests the key factors affecting the activity and durability of electrodeposited Co-based OER catalysts in both KOH and pure-water media. By comparing the electrochemical behavior and catalyst synthesis strategies under these conditions, we identify performance bottlenecks and knowledge gaps and propose strategies to guide the rational design of robust Co-based catalysts for sustainable AEMWE systems.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3128–3140"},"PeriodicalIF":8.7,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yufan Xiao, Fangjie Sun, Wenyue Dong*, Qian Duan, Changming Chen* and Teng Fei*,
{"title":"Rewritable Polymer Optical Waveguide Chip Based on Photoisomerization Feature of Photosensitive Chromophore","authors":"Yufan Xiao, Fangjie Sun, Wenyue Dong*, Qian Duan, Changming Chen* and Teng Fei*, ","doi":"10.1021/acsmaterialslett.5c00744","DOIUrl":"https://doi.org/10.1021/acsmaterialslett.5c00744","url":null,"abstract":"<p >The core layer of an optical waveguide device was fabricated by doping the photosensitive chromophore spiropyran derivative SP-Br into poly(methyl methacrylate) (PMMA). The design of the core layer allows us to precisely control the optical property of the waveguide using the photoisomerization process of SP-Br. Under UV excitation, the controllable conversion between SP-Br and the merocyanine isomer MC-Br allows dynamic and continuous changes in the refractive index, thus enabling the function of repeated writing and erasing of optical paths in the optical waveguide device. The ability to dynamically adjust the refractive index provides unprecedented flexibility in the design and fabrication of an optical waveguide device.</p>","PeriodicalId":19,"journal":{"name":"ACS Materials Letters","volume":"7 9","pages":"3120–3127"},"PeriodicalIF":8.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}