@article{15182, abstract = {Thermoelectric materials convert heat into electricity, with a broad range of applications near room temperature (RT). However, the library of RT high-performance materials is limited. Traditional high-temperature synthetic methods constrain the range of materials achievable, hindering the ability to surpass crystal structure limitations and engineer defects. Here, a solution-based synthetic approach is introduced, enabling RT synthesis of powders and exploration of densification at lower temperatures to influence the material's microstructure. The approach is exemplified by Ag2Se, an n-type alternative to bismuth telluride. It is demonstrated that the concentration of Ag interstitials, grain boundaries, and dislocations are directly correlated to the sintering temperature, and achieve a figure of merit of 1.1 from RT to 100 °C after optimization. Moreover, insights into and resolve Ag2Se's challenges are provided, including stoichiometry issues leading to irreproducible performances. This work highlights the potential of RT solution synthesis in expanding the repertoire of high-performance thermoelectric materials for practical applications.}, author = {Kleinhanns, Tobias and Milillo, Francesco and Calcabrini, Mariano and Fiedler, Christine and Horta, Sharona and Balazs, Daniel and Strumolo, Marissa J. and Hasler, Roger and Llorca, Jordi and Tkadletz, Michael and Brutchey, Richard L. and Ibáñez, Maria}, issn = {1614-6840}, journal = {Advanced Energy Materials}, publisher = {Wiley}, title = {{A route to high thermoelectric performance: Solution‐based control of microstructure and composition in Ag2Se}}, doi = {10.1002/aenm.202400408}, year = {2024}, } @article{14404, abstract = {A light-triggered fabrication method extends the functionality of printable nanomaterials}, author = {Balazs, Daniel and Ibáñez, Maria}, issn = {1095-9203}, journal = {Science}, number = {6665}, pages = {1413--1414}, publisher = {AAAS}, title = {{Widening the use of 3D printing}}, doi = {10.1126/science.adk3070}, volume = {381}, year = {2023}, } @article{14799, abstract = {A round-robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5% and half of the population width entries within 40%. Due to the added complexity of the structure factor, far fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 and 86%, respectively. This round-robin experiment highlights several causes for the discrepancies, for which solutions are proposed.}, author = {Pauw, Brian R. and Smales, Glen J. and Anker, Andy S. and Annadurai, Venkatasamy and Balazs, Daniel and Bienert, Ralf and Bouwman, Wim G. and Breßler, Ingo and Breternitz, Joachim and Brok, Erik S. and Bryant, Gary and Clulow, Andrew J. and Crater, Erin R. and De Geuser, Frédéric and Giudice, Alessandra Del and Deumer, Jérôme and Disch, Sabrina and Dutt, Shankar and Frank, Kilian and Fratini, Emiliano and Garcia, Paulo R.A.F. and Gilbert, Elliot P. and Hahn, Marc B. and Hallett, James and Hohenschutz, Max and Hollamby, Martin and Huband, Steven and Ilavsky, Jan and Jochum, Johanna K. and Juelsholt, Mikkel and Mansel, Bradley W. and Penttilä, Paavo and Pittkowski, Rebecca K. and Portale, Giuseppe and Pozzo, Lilo D. and Rochels, Leonhard and Rosalie, Julian M. and Saloga, Patrick E.J. and Seibt, Susanne and Smith, Andrew J. and Smith, Gregory N. and Spiering, Glenn A. and Stawski, Tomasz M. and Taché, Olivier and Thünemann, Andreas F. and Toth, Kristof and Whitten, Andrew E. and Wuttke, Joachim}, issn = {1600-5767}, journal = {Journal of Applied Crystallography}, number = {6}, pages = {1618--1629}, title = {{The human factor: Results of a small-angle scattering data analysis round robin}}, doi = {10.1107/S1600576723008324}, volume = {56}, year = {2023}, } @article{10587, abstract = {Access to a blossoming library of colloidal nanomaterials provides building blocks for complex assembled materials. The journey to bring these prospects to fruition stands to benefit from the application of advanced processing methods. Epitaxially connected nanocrystal (or quantum dot) superlattices present a captivating model system for mesocrystals with intriguing emergent properties. The conventional processing approach to creating these materials involves assembling and attaching the constituent nanocrystals at the interface between two immiscible fluids. Processing small liquid volumes of the colloidal nanocrystal solution involves several complexities arising from the concurrent spreading, evaporation, assembly, and attachment. The ability of inkjet printers to deliver small (typically picoliter) liquid volumes with precise positioning is attractive to advance fundamental insights into the processing science, and thereby potentially enable new routes to incorporate the epitaxially connected superlattices into technology platforms. In this study, we identified the processing window of opportunity, including nanocrystal ink formulation and printing approach to enable delivery of colloidal nanocrystals from an inkjet nozzle onto the surface of a sessile droplet of the immiscible subphase. We demonstrate how inkjet printing can be scaled-down to enable the fabrication of epitaxially connected superlattices on patterned sub-millimeter droplets. We anticipate that insights from this work will spur on future advances to enable more mechanistic insights into the assembly processes and new avenues to create high-fidelity superlattices.}, author = {Balazs, Daniel and Erkan, N. Deniz and Quien, Michelle and Hanrath, Tobias}, issn = {1998-0000}, journal = {Nano Research}, keywords = {interfacial assembly, colloidal nanocrystal, superlattice, inkjet printing}, number = {5}, pages = {4536–4543}, publisher = {Springer Nature}, title = {{Inkjet printing of epitaxially connected nanocrystal superlattices}}, doi = {10.1007/s12274-021-4022-7}, volume = {15}, year = {2022}, } @article{9829, abstract = {In 2020, many in-person scientific events were canceled due to the COVID-19 pandemic, creating a vacuum in networking and knowledge exchange between scientists. To fill this void in scientific communication, a group of early career nanocrystal enthusiasts launched the virtual seminar series, News in Nanocrystals, in the summer of 2020. By the end of the year, the series had attracted over 850 participants from 46 countries. In this Nano Focus, we describe the process of organizing the News in Nanocrystals seminar series; discuss its growth, emphasizing what the organizers have learned in terms of diversity and accessibility; and provide an outlook for the next steps and future opportunities. This summary and analysis of experiences and learned lessons are intended to inform the broader scientific community, especially those who are looking for avenues to continue fostering discussion and scientific engagement virtually, both during the pandemic and after.}, author = {Baranov, Dmitry and Šverko, Tara and Moot, Taylor and Keller, Helena R. and Klein, Megan D. and Vishnu, E. K. and Balazs, Daniel and Shulenberger, Katherine E.}, issn = {1936086X}, journal = {ACS Nano}, number = {7}, pages = {10743–10747}, publisher = {American Chemical Society}, title = {{News in Nanocrystals seminar: Self-assembly of early career researchers toward globally accessible nanoscience}}, doi = {10.1021/acsnano.1c03276}, volume = {15}, year = {2021}, } @article{10534, abstract = {For many years, fullerene derivatives have been the main n-type material of organic electronics and optoelectronics. Recently, fullerene derivatives functionalized with ethylene glycol (EG) side chains have been showing important properties such as enhanced dielectric constants, facile doping and enhanced self-assembly capabilities. Here, we have prepared field-effect transistors using a series of these fullerene derivatives equipped with EG side chains of different lengths. Transport data show the beneficial effect of increasing the EG side chain. In order to understand the material properties, full structural determination of these fullerene derivatives has been achieved by coupling the X-ray data with molecular dynamics (MD) simulations. The increase in transport properties is paired with the formation of extended layered structures, efficient molecular packing and an increase in the crystallite alignment. The layer-like structure is composed of conducting layers, containing of closely packed C60 balls approaching the inter-distance of 1 nm, that are separated by well-defined EG layers, where the EG chains are rather splayed with the chain direction almost perpendicular to the layer normal. Such a layered structure appears highly ordered and highly aligned with the C60 planes oriented parallel to the substrate in the thin film configuration. The order inside the thin film increases with the EG chain length, allowing the systems to achieve mobilities as high as 0.053 cm2 V−1 s−1. Our work elucidates the structure of these interesting semiconducting organic molecules and shows that the synergistic use of X-ray structural analysis and MD simulations is a powerful tool to identify the structure of thin organic films for optoelectronic applications.}, author = {Dong, Jingjin and Sami, Selim and Balazs, Daniel and Alessandri, Riccardo and Jahani, Fatimeh and Qiu, Li and Marrink, Siewert J. and Havenith, Remco W.A. and Hummelen, Jan C. and Loi, Maria A. and Portale, Giuseppe}, issn = {2050-7526}, journal = {Journal of Materials Chemistry C}, number = {45}, pages = {16217--16225}, publisher = {Royal Society of Chemistry}, title = {{Fullerene derivatives with oligoethylene-glycol side chains: An investigation on the origin of their outstanding transport properties}}, doi = {10.1039/d1tc02753k}, volume = {9}, year = {2021}, }