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1. Nanoconfining solution-processed organic semiconductors for emerging optoelectronics

   https://doi.org/10.1039/D1CS00430A  

   Zhang, Yuze; Chen, Alina; Kim, Min-Woo; Alaei, Aida; Lee, Stephanie S. (August 2021, Chemical Society Reviews)

   Solution-processable organic materials for emerging electronics can generally be divided into two classes of semiconductors, organic small molecules and polymers. The theoretical thermodynamic limits of device performance are largely determined by the molecular structure of these compounds, and advances in synthetic routes have led to significant progress in charge mobilities and light conversion and light emission efficiencies over the past several decades. Still, the uncontrolled formation of out-of-equilibrium film microstructures and unfavorable polymorphs during rapid solution processing remains a critical bottleneck facing the commercialization of these materials. This tutorial review provides an overview of the use of nanoconfining scaffolds to impose order onto solution-processed semiconducting films to overcome this limitation. For organic semiconducting small molecules and polymers, which typically exhibit strong crystal growth and charge transport anisotropy along different crystallographic directions, nanoconfining crystallization within nanopores and nanogrooves can preferentially orient the fast charge transport direction of crystals with the direction of current flow in devices. Nanoconfinement can also stabilize high-performance metastable polymorphs by shifting their relative Gibbs free energies via increasing the surface area-to-volume ratio. Promisingly, such nanoconfinement-induced improvements in film and crystal structures have been demonstrated to enhance the performance and stability of emerging optoelectronics that will enable large-scale manufacturing of flexible, lightweight displays and solar cells. 

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2. Advanced Electrical and Optical Microsystems for Biointerfacing

   https://doi.org/10.1002/aisy.202000091  

   Obaid, Sofian_N; Chen, Zhiyuan; Lu, Luyao (July 2020, Advanced Intelligent Systems)

   Electrical and optical biointerfaces have contributed considerably to understanding biological systems. Recent advances in biocompatible materials, structure designs, and fabrication techniques have established flexible and minimally invasive electronic/optoelectronic platforms that laminate onto targeted surface regions or implant into precise locations of biosystems to monitor and control various biological processes at cell, tissue, and organ levels. Herein, recent progress in advanced biointegrated electrical and optical platforms is discussed. An overview of materials and device designs to form flexible and even stretchable electrodes is presented. Strategies to reduce tissue damage and foreign‐body response to improve chronic stability are described. State‐of‐the‐art wearable and implantable microsystems with/without wireless capabilities for bioelectrical sensing and stimulation, optical recording and modulation, and multimodal operation are highlighted. In conclusion, a discussion of the remaining obstacles for future research in these areas is provided. 

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3. Efficient Low Cost Alternative Testing of Analog Crossbar Arrays for Deep Neural Networks

   Kwondo Ma, Anurup Saha (September 2022, International Test Conference)

   Analog crossbar arrays have recently attracted significant attention due to their usefulness for deep neural net (DNN) computations with ultra-low power consumption. However, recent studies have shown that DNNs implemented with such crossbar arrays suffer from as high as 30% degradation in performance due to the effects of manufacturing process variability effects resulting in degradation of their functional safety. One way to test these DNNs is to apply an exhaustive set of test images to each device to ascertain its performance. This is expensive and time-consuming. We propose an alternative test scheme in which a small subset of test images is applied to each DNN and the classification accuracy of the DNN is predicted directly from observation of the final layer outputs of the network. This saves test cost while allowing binning of DNNs for performance. Experimental results for a variety of test cases are presented and show test efficiency improvements of 3X over testing with the exhaustive test image set. 

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4. New Directions for Thermoelectrics: A Roadmap from High‐Throughput Materials Discovery to Advanced Device Manufacturing

   https://doi.org/10.1002/smsc.202300359  

   Song, Kaidong; Tanvir, Ali_Newaz_Mohammad; Bappy, Md_Omarsany; Zhang, Yanliang (April 2024, Small Science)

   Thermoelectric materials, which can convert waste heat into electricity or act as solid‐state Peltier coolers, are emerging as key technologies to address global energy shortages and environmental sustainability. However, discovering materials with high thermoelectric conversion efficiency is a complex and slow process. The emerging field of high‐throughput material discovery demonstrates its potential to accelerate the development of new thermoelectric materials combining high efficiency and low cost. The synergistic integration of high‐throughput material processing and characterization techniques with machine learning algorithms can form an efficient closed‐loop process to generate and analyze broad datasets to discover new thermoelectric materials with unprecedented performances. Meanwhile, the recent development of advanced manufacturing methods provides exciting opportunities to realize scalable, low‐cost, and energy‐efficient fabrication of thermoelectric devices. This review provides an overview of recent advances in discovering thermoelectric materials using high‐throughput methods, including processing, characterization, and screening. Advanced manufacturing methods of thermoelectric devices are also introduced to realize the broad impacts of thermoelectric materials in power generation and solid‐state cooling. In the end, this article also discusses the future research prospects and directions. 

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5. Scalable nanomanufacturing of chalcogenide inks: a case study on thermoelectric V–VI nanoplates

   https://doi.org/10.1039/d1ta05858d  

   Zeng, Minxiang; Xie, Hongyao; Saeidi-Javash, Mortaza; Tanvir, A.N.M.; Du, Yipu; Chen, Jiahao; Kanatzidis, Mercouri G.; Zhang, Yanliang (October 2021, Journal of Materials Chemistry A)

   null (Ed.)

   Solution-processed semiconducting main-group chalcogenides (MMCs) have attracted increasing research interest for next-generation device technologies owing to their unique nanostructures and superior properties. To achieve the full potential of MMCs, the development of highly universal, scalable, and sustainable synthesis and processing methods of chalcogenide particles is thus becoming progressively more important. Here we studied scalable factors for the synthesis of two-dimensional (2D) V–VI chalcogenide nanoplates (M 2 Q 3  : M = Sb, Bi; Q = Se, Te) and systematically investigated their colloidal behaviour and chemical stability. Based on a solvent engineering technique, we demonstrated scale-up syntheses of MMCs up to a 900% increase of batch size compared with conventional hydrazine-based gram-level syntheses, and such a scalable approach is highly applicable to various binary and ternary MMCs. Furthermore, we studied the stability of printable chalcogenide nanoparticle inks with several formulation factors including solvents, additives, and pH values, resulting in inks with high chemical stability (>4 months). As a proof of concept, we applied our solution-processed chalcogenide particles to multiple additive manufacturing methods, confirming the high printability and processability of MMC inks. The ability to combine the top-down designing freedom of additive manufacturing with bottom-up scalable synthesis of chalcogenide particles promises great opportunities for large-scale design and manufacturing of chalcogenide-based functional devices for broad application. 

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