@phdthesis{12885, abstract = {High-performance semiconductors rely upon precise control of heat and charge transport. This can be achieved by precisely engineering defects in polycrystalline solids. There are multiple approaches to preparing such polycrystalline semiconductors, and the transformation of solution-processed colloidal nanoparticles is appealing because colloidal nanoparticles combine low cost with structural and compositional tunability along with rich surface chemistry. However, the multiple processes from nanoparticle synthesis to the final bulk nanocomposites are very complex. They involve nanoparticle purification, post-synthetic modifications, and finally consolidation (thermal treatments and densification). All these properties dictate the final material’s composition and microstructure, ultimately affecting its functional properties. This thesis explores the synthesis, surface chemistry and consolidation of colloidal semiconductor nanoparticles into dense solids. In particular, the transformations that take place during these processes, and their effect on the material’s transport properties are evaluated. }, author = {Calcabrini, Mariano}, isbn = {978-3-99078-028-2}, issn = {2663-337X}, pages = {82}, publisher = {Institute of Science and Technology Austria}, title = {{Nanoparticle-based semiconductor solids: From synthesis to consolidation}}, doi = {10.15479/at:ista:12885}, year = {2023}, } @article{12915, abstract = {Cu2–xS and Cu2–xSe have recently been reported as promising thermoelectric (TE) materials for medium-temperature applications. In contrast, Cu2–xTe, another member of the copper chalcogenide family, typically exhibits low Seebeck coefficients that limit its potential to achieve a superior thermoelectric figure of merit, zT, particularly in the low-temperature range where this material could be effective. To address this, we investigated the TE performance of Cu1.5–xTe–Cu2Se nanocomposites by consolidating surface-engineered Cu1.5Te nanocrystals. This surface engineering strategy allows for precise adjustment of Cu/Te ratios and results in a reversible phase transition at around 600 K in Cu1.5–xTe–Cu2Se nanocomposites, as systematically confirmed by in situ high-temperature X-ray diffraction combined with differential scanning calorimetry analysis. The phase transition leads to a conversion from metallic-like to semiconducting-like TE properties. Additionally, a layer of Cu2Se generated around Cu1.5–xTe nanoparticles effectively inhibits Cu1.5–xTe grain growth, minimizing thermal conductivity and decreasing hole concentration. These properties indicate that copper telluride based compounds have a promising thermoelectric potential, translated into a high dimensionless zT of 1.3 at 560 K.}, author = {Xing, Congcong and Zhang, Yu and Xiao, Ke and Han, Xu and Liu, Yu and Nan, Bingfei and Ramon, Maria Garcia and Lim, Khak Ho and Li, Junshan and Arbiol, Jordi and Poudel, Bed and Nozariasbmarz, Amin and Li, Wenjie and Ibáñez, Maria and Cabot, Andreu}, issn = {1936-086X}, journal = {ACS Nano}, number = {9}, pages = {8442--8452}, publisher = {American Chemical Society}, title = {{Thermoelectric performance of surface-engineered Cu1.5–xTe–Cu2Se nanocomposites}}, doi = {10.1021/acsnano.3c00495}, volume = {17}, year = {2023}, } @article{10829, abstract = {A novel multivariable system, combining a transistor with fiber optic-based surface plasmon resonance spectroscopy with the gate electrode simultaneously acting as the fiber optic sensor surface, is reported. The dual-mode sensor allows for discrimination of mass and charge contributions for binding assays on the same sensor surface. Furthermore, we optimize the sensor geometry by investigating the influence of the fiber area to transistor channel area ratio and distance. We show that larger fiber optic tip diameters are favorable for electronic and optical signals and demonstrate the reversibility of plasmon resonance wavelength shifts after electric field application. As a proof of principle, a layer-by-layer assembly of polyelectrolytes is performed to benchmark the system against multivariable sensing platforms with planar surface plasmon resonance configurations. Furthermore, the biosensing performance is assessed using a thrombin binding assay with surface-immobilized aptamers as receptors, allowing for the detection of medically relevant thrombin concentrations.}, author = {Hasler, Roger and Reiner-Rozman, Ciril and Fossati, Stefan and Aspermair, Patrik and Dostalek, Jakub and Lee, Seungho and Ibáñez, Maria and Bintinger, Johannes and Knoll, Wolfgang}, issn = {23793694}, journal = {ACS Sensors}, number = {2}, pages = {504--512}, publisher = {American Chemical Society}, title = {{Field-effect transistor with a plasmonic fiber optic gate electrode as a multivariable biosensor device}}, doi = {10.1021/acssensors.1c02313}, volume = {7}, year = {2022}, } @misc{10833, abstract = {Detailed information about the data set see "dataset description.txt" file.}, author = {Hasler, Roger and Reiner-Rozman, Ciril and Fossati, Stefan and Aspermair, Patrik and Dostalek, Jakub and Lee, Seungho and Ibáñez, Maria and Bintinger, Johannes and Knoll, Wolfgang}, publisher = {Zenodo}, title = {{Field-effect transistor with a plasmonic fiber optic gate electrode as a multivariable biosensor device}}, doi = {10.5281/ZENODO.5500360}, year = {2022}, } @article{11142, abstract = {SnTe is a promising Pb-free thermoelectric (TE) material with high electrical conductivity. We discovered the synergistic effect of Bi2O3 on enhancing the average power factor (PF) and overall ZT value of the SnTe-based thermoelectric material. The introduction of Bi2O3 forms plenty of SnO2, Bi2O3, and Bi-rich nanoprecipitates. These interfaces between the SnTe matrix and the nanoprecipitates can enhance the average PF through the energy filtering effect. On the other hand, abundant and diverse nanoprecipitates can significantly diminish the lattice thermal conductivity (κlat) through enhanced phonon scattering. The synergistic effect of Bi2O3 resulted in a maximum ZT (ZTmax) value of 0.9 at SnTe-2% Bi2O3 and an average ZT (ZTave) value of 0.4 for SnTe-4% Bi2O3 from 300 K to 823 K. The work provides an excellent reference to develop non-toxic high-performance TE materials.}, author = {Hong, Tao and Guo, Changrong and Wang, Dongyang and Qin, Bingchao and Chang, Cheng and Gao, Xiang and Zhao, Li Dong}, issn = {2468-6069}, journal = {Materials Today Energy}, publisher = {Elsevier}, title = {{Enhanced thermoelectric performance in SnTe due to the energy filtering effect introduced by Bi2O3}}, doi = {10.1016/j.mtener.2022.100985}, volume = {25}, year = {2022}, } @article{11144, abstract = {Thermoelectric materials allow for direct conversion between heat and electricity, offering the potential for power generation. The average dimensionless figure of merit ZTave determines device efficiency. N-type tin selenide crystals exhibit outstanding three-dimensional charge and two-dimensional phonon transport along the out-of-plane direction, contributing to a high maximum figure of merit Zmax of ~3.6 × 10−3 per kelvin but a moderate ZTave of ~1.1. We found an attractive high Zmax of ~4.1 × 10−3 per kelvin at 748 kelvin and a ZTave of ~1.7 at 300 to 773 kelvin in chlorine-doped and lead-alloyed tin selenide crystals by phonon-electron decoupling. The chlorine-induced low deformation potential improved the carrier mobility. The lead-induced mass and strain fluctuations reduced the lattice thermal conductivity. Phonon-electron decoupling plays a critical role to achieve high-performance thermoelectrics.}, author = {Su, Lizhong and Wang, Dongyang and Wang, Sining and Qin, Bingchao and Wang, Yuping and Qin, Yongxin and Jin, Yang and Chang, Cheng and Zhao, Li Dong}, issn = {1095-9203}, journal = {Science}, number = {6587}, pages = {1385--1389}, publisher = {American Association for the Advancement of Science}, title = {{High thermoelectric performance realized through manipulating layered phonon-electron decoupling}}, doi = {10.1126/science.abn8997}, volume = {375}, year = {2022}, } @article{11356, author = {Chang, Cheng and Qin, Bingchao and Su, Lizhong and Zhao, Li Dong}, issn = {2095-9281}, journal = {Science Bulletin}, number = {11}, pages = {1105--1107}, publisher = {Elsevier}, title = {{Distinct electron and hole transports in SnSe crystals}}, doi = {10.1016/j.scib.2022.04.007}, volume = {67}, year = {2022}, } @article{11401, abstract = {Tin selenide (SnSe) is considered a robust candidate for thermoelectric applications due to its very high thermoelectric figure of merit, ZT, with values of 2.6 in p-type and 2.8 in n-type single crystals. Sn has been replaced with various lower group dopants to achieve successful p-type doping in SnSe with high ZT values. A known, facile, and powerful alternative way to introduce a hole carrier is to use a natural single Sn vacancy, VSn. Through transport and scanning tunneling microscopy studies, we discovered that VSn are dominant in high-quality (slow cooling rate) SnSe single crystals, while multiple vacancies, Vmulti, are dominant in low-quality (high cooling rate) single crystals. Surprisingly, both VSn and Vmulti help to increase the power factors of SnSe, whereas samples with dominant VSn have superior thermoelectric properties in SnSe single crystals. Additionally, the observation that Vmulti are good p-type sources observed in relatively low-quality single crystals is useful in thermoelectric applications because polycrystalline SnSe can be used due to its mechanical strength; this substance is usually fabricated at very high cooling speeds.}, author = {Nguyen, Van Quang and Trinh, Thi Ly and Chang, Cheng and Zhao, Li Dong and Nguyen, Thi Huong and Duong, Van Thiet and Duong, Anh Tuan and Park, Jong Ho and Park, Sudong and Kim, Jungdae and Cho, Sunglae}, issn = {1884-4057}, journal = {NPG Asia Materials}, publisher = {Springer Nature}, title = {{Unidentified major p-type source in SnSe: Multivacancies}}, doi = {10.1038/s41427-022-00393-5}, volume = {14}, year = {2022}, } @article{11451, abstract = {The precursor conversion chemistry and surface chemistry of Cu3N and Cu3PdN nanocrystals are unknown or contested. Here, we first obtain phase-pure, colloidally stable nanocubes. Second, we elucidate the pathway by which copper(II) nitrate and oleylamine form Cu3N. We find that oleylamine is both a reductant and a nitrogen source. Oleylamine is oxidized by nitrate to a primary aldimine, which reacts further with excess oleylamine to a secondary aldimine, eliminating ammonia. Ammonia reacts with CuI to form Cu3N. Third, we investigated the surface chemistry and find a mixed ligand shell of aliphatic amines and carboxylates (formed in situ). While the carboxylates appear tightly bound, the amines are easily desorbed from the surface. Finally, we show that doping with palladium decreases the band gap and the material becomes semi-metallic. These results bring insight into the chemistry of metal nitrides and might help the development of other metal nitride nanocrystals.}, author = {Parvizian, Mahsa and Duràn Balsa, Alejandra and Pokratath, Rohan and Kalha, Curran and Lee, Seungho and Van Den Eynden, Dietger and Ibáñez, Maria and Regoutz, Anna and De Roo, Jonathan}, issn = {1521-3773}, journal = {Angewandte Chemie - International Edition}, number = {31}, publisher = {Wiley}, title = {{The chemistry of Cu₃N and Cu₃PdN nanocrystals}}, doi = {10.1002/anie.202207013}, volume = {61}, year = {2022}, } @misc{11695, abstract = {Data underlying the figures in the publication "The chemistry of Cu3N and Cu3PdN nanocrystals" }, author = {Parvizian, Mahsa and Duran Balsa, Alejandra and Pokratath, Rohan and Kalha, Curran and Lee, Seungho and Van den Eynden, Dietger and Ibáñez, Maria and Regoutz, Anna and De Roo, Jonathan}, publisher = {Zenodo}, title = {{Data for "The chemistry of Cu3N and Cu3PdN nanocrystals"}}, doi = {10.5281/ZENODO.6542908}, year = {2022}, } @article{11705, abstract = {The broad implementation of thermoelectricity requires high-performance and low-cost materials. One possibility is employing surfactant-free solution synthesis to produce nanopowders. We propose the strategy of functionalizing “naked” particles’ surface by inorganic molecules to control the nanostructure and, consequently, thermoelectric performance. In particular, we use bismuth thiolates to functionalize surfactant-free SnTe particles’ surfaces. Upon thermal processing, bismuth thiolates decomposition renders SnTe-Bi2S3 nanocomposites with synergistic functions: 1) carrier concentration optimization by Bi doping; 2) Seebeck coefficient enhancement and bipolar effect suppression by energy filtering; and 3) lattice thermal conductivity reduction by small grain domains, grain boundaries and nanostructuration. Overall, the SnTe-Bi2S3 nanocomposites exhibit peak z T up to 1.3 at 873 K and an average z T of ≈0.6 at 300–873 K, which is among the highest reported for solution-processed SnTe.}, author = {Chang, Cheng and Liu, Yu and Lee, Seungho and Spadaro, Maria and Koskela, Kristopher M. and Kleinhanns, Tobias and Costanzo, Tommaso and Arbiol, Jordi and Brutchey, Richard L. and Ibáñez, Maria}, issn = {1521-3773}, journal = {Angewandte Chemie - International Edition}, number = {35}, publisher = {Wiley}, title = {{Surface functionalization of surfactant-free particles: A strategy to tailor the properties of nanocomposites for enhanced thermoelectric performance}}, doi = {10.1002/anie.202207002}, volume = {61}, year = {2022}, } @article{14437, abstract = {Future LEDs could be based on lead halide perovskites. A breakthrough in preparing device-compatible solids composed of nanoscale perovskite crystals overcomes a long-standing hurdle in making blue perovskite LEDs.}, author = {Utzat, Hendrik and Ibáñez, Maria}, issn = {1476-4687}, journal = {Nature}, keywords = {Multidisciplinary}, number = {7941}, pages = {638--639}, publisher = {Springer Nature}, title = {{Molecular engineering enables bright blue LEDs}}, doi = {10.1038/d41586-022-04447-0}, volume = {612}, year = {2022}, } @article{10042, abstract = {SnSe has emerged as one of the most promising materials for thermoelectric energy conversion due to its extraordinary performance in its single-crystal form and its low-cost constituent elements. However, to achieve an economic impact, the polycrystalline counterpart needs to replicate the performance of the single crystal. Herein, we optimize the thermoelectric performance of polycrystalline SnSe produced by consolidating solution-processed and surface-engineered SnSe particles. In particular, the SnSe particles are coated with CdSe molecular complexes that crystallize during the sintering process, forming CdSe nanoparticles. The presence of CdSe nanoparticles inhibits SnSe grain growth during the consolidation step due to Zener pinning, yielding a material with a high density of grain boundaries. Moreover, the resulting SnSe–CdSe nanocomposites present a large number of defects at different length scales, which significantly reduce the thermal conductivity. The produced SnSe–CdSe nanocomposites exhibit thermoelectric figures of merit up to 2.2 at 786 K, which is among the highest reported for solution-processed SnSe.}, author = {Liu, Yu and Calcabrini, Mariano and Yu, Yuan and Lee, Seungho and Chang, Cheng and David, Jérémy and Ghosh, Tanmoy and Spadaro, Maria Chiara and Xie, Chenyang and Cojocaru-Mirédin, Oana and Arbiol, Jordi and Ibáñez, Maria}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {tin selenide, nanocomposite, grain growth, Zener pinning, thermoelectricity, annealing, solution processing}, number = {1}, pages = {78--88}, publisher = {American Chemical Society }, title = {{Defect engineering in solution-processed polycrystalline SnSe leads to high thermoelectric performance}}, doi = {10.1021/acsnano.1c06720}, volume = {16}, year = {2022}, } @article{10566, abstract = {A versatile, scalable, room temperature and surfactant-free route for the synthesis of metal chalcogenide nanoparticles in aqueous solution is detailed here for the production of PbS and Cu-doped PbS nanoparticles. Subsequently, nanoparticles are annealed in a reducing atmosphere to remove surface oxide, and consolidated into dense polycrystalline materials by means of spark plasma sintering. By characterizing the transport properties of the sintered material, we observe the annealing step and the incorporation of Cu to play a key role in promoting the thermoelectric performance of PbS. The presence of Cu allows improving the electrical conductivity by increasing the charge carrier concentration and simultaneously maintaining a large charge carrier mobility, which overall translates into record power factors at ambient temperature, 2.3 mWm-1K−2. Simultaneously, the lattice thermal conductivity decreases with the introduction of Cu, leading to a record high ZT = 0.37 at room temperature and ZT = 1.22 at 773 K. Besides, a record average ZTave = 0.76 is demonstrated in the temperature range 320–773 K for n-type Pb0.955Cu0.045S.}, author = {Li, Mengyao and Liu, Yu and Zhang, Yu and Chang, Cheng and Zhang, Ting and Yang, Dawei and Xiao, Ke and Arbiol, Jordi and Ibáñez, Maria and Cabot, Andreu}, issn = {1385-8947}, journal = {Chemical Engineering Journal}, publisher = {Elsevier}, title = {{Room temperature aqueous-based synthesis of copper-doped lead sulfide nanoparticles for thermoelectric application}}, doi = {10.1016/j.cej.2021.133837}, volume = {433}, year = {2022}, } @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{12155, abstract = {The growing demand of thermal management in various fields such as miniaturized 5G chips has motivated researchers to develop new and high-performance solid-state refrigeration technologies, typically including multicaloric and thermoelectric (TE) cooling. Among them, TE cooling has attracted huge attention owing to its advantages of rapid response, large cooling temperature difference, high stability, and tunable device size. Bi2Te3-based alloys have long been the only commercialized TE cooling materials, while novel systems SnSe and Mg3(Bi,Sb)2 have recently been discovered as potential candidates. However, challenges and problems still require to be summarized and further resolved for realizing better cooling performance. In this review, we systematically investigate TE cooling from its internal mechanism, crucial parameters, to device design and applications. Furthermore, we summarize the current optimization strategies for existing TE cooling materials, and finally provide some personal prospects especially the material-planification concept on future research on establishing better TE cooling.}, author = {Qin, Yongxin and Qin, Bingchao and Wang, Dongyang and Chang, Cheng and Zhao, Li-Dong}, issn = {1754-5706}, journal = {Energy & Environmental Science}, keywords = {Pollution, Nuclear Energy and Engineering, Renewable Energy, Sustainability and the Environment, Environmental Chemistry}, number = {11}, pages = {4527--4541}, publisher = {Royal Society of Chemistry}, title = {{Solid-state cooling: Thermoelectrics}}, doi = {10.1039/d2ee02408j}, volume = {15}, year = {2022}, } @article{12236, abstract = {High-entropy materials offer numerous advantages as catalysts, including a flexible composition to tune the catalytic activity and selectivity and a large variety of adsorption/reaction sites for multistep or multiple reactions. Herein, we report on the synthesis, properties, and electrocatalytic performance of an amorphous high-entropy boride based on abundant transition metals, CoFeNiMnZnB. This metal boride provides excellent performance toward the oxygen evolution reaction (OER), including a low overpotential of 261 mV at 10 mA cm–2, a reduced Tafel slope of 56.8 mV dec–1, and very high stability. The outstanding OER performance of CoFeNiMnZnB is attributed to the synergistic interactions between the different metals, the leaching of Zn ions, the generation of oxygen vacancies, and the in situ formation of an amorphous oxyhydroxide at the CoFeNiMnZnB surface during the OER.}, author = {Wang, Xiang and Zuo, Yong and Horta, Sharona and He, Ren and Yang, Linlin and Ostovari Moghaddam, Ahmad and Ibáñez, Maria and Qi, Xueqiang and Cabot, Andreu}, issn = {1944-8252}, journal = {ACS Applied Materials & Interfaces}, keywords = {General Materials Science}, number = {42}, pages = {48212--48219}, publisher = {American Chemical Society}, title = {{CoFeNiMnZnB as a high-entropy metal boride to boost the oxygen evolution reaction}}, doi = {10.1021/acsami.2c11627}, volume = {14}, year = {2022}, } @article{12237, abstract = {Thermoelectric technology requires synthesizing complex materials where not only the crystal structure but also other structural features such as defects, grain size and orientation, and interfaces must be controlled. To date, conventional solid-state techniques are unable to provide this level of control. Herein, we present a synthetic approach in which dense inorganic thermoelectric materials are produced by the consolidation of well-defined nanoparticle powders. The idea is that controlling the characteristics of the powder allows the chemical transformations that take place during consolidation to be guided, ultimately yielding inorganic solids with targeted features. Different from conventional methods, syntheses in solution can produce particles with unprecedented control over their size, shape, crystal structure, composition, and surface chemistry. However, to date, most works have focused only on the low-cost benefits of this strategy. In this perspective, we first cover the opportunities that solution processing of the powder offers, emphasizing the potential structural features that can be controlled by precisely engineering the inorganic core of the particle, the surface, and the organization of the particles before consolidation. We then discuss the challenges of this synthetic approach and more practical matters related to solution processing. Finally, we suggest some good practices for adequate knowledge transfer and improving reproducibility among different laboratories.}, author = {Fiedler, Christine and Kleinhanns, Tobias and Garcia, Maria and Lee, Seungho and Calcabrini, Mariano and Ibáñez, Maria}, issn = {1520-5002}, journal = {Chemistry of Materials}, keywords = {Materials Chemistry, General Chemical Engineering, General Chemistry}, number = {19}, pages = {8471--8489}, publisher = {American Chemical Society}, title = {{Solution-processed inorganic thermoelectric materials: Opportunities and challenges}}, doi = {10.1021/acs.chemmater.2c01967}, volume = {34}, year = {2022}, } @article{10806, abstract = {Ligands are a fundamental part of nanocrystals. They control and direct nanocrystal syntheses and provide colloidal stability. Bound ligands also affect the nanocrystals’ chemical reactivity and electronic structure. Surface chemistry is thus crucial to understand nanocrystal properties and functionality. Here, we investigate the synthesis of metal oxide nanocrystals (CeO2-x, ZnO, and NiO) from metal nitrate precursors, in the presence of oleylamine ligands. Surprisingly, the nanocrystals are capped exclusively with a fatty acid instead of oleylamine. Analysis of the reaction mixtures with nuclear magnetic resonance spectroscopy revealed several reaction byproducts and intermediates that are common to the decomposition of Ce, Zn, Ni, and Zr nitrate precursors. Our evidence supports the oxidation of alkylamine and formation of a carboxylic acid, thus unraveling this counterintuitive surface chemistry.}, author = {Calcabrini, Mariano and Van den Eynden, Dietger and Sanchez Ribot, Sergi and Pokratath, Rohan and Llorca, Jordi and De Roo, Jonathan and Ibáñez, Maria}, issn = {2691-3704}, journal = {JACS Au}, keywords = {general medicine}, number = {11}, pages = {1898--1903}, publisher = {American Chemical Society}, title = {{Ligand conversion in nanocrystal synthesis: The oxidation of alkylamines to fatty acids by nitrate}}, doi = {10.1021/jacsau.1c00349}, volume = {1}, year = {2021}, } @article{10809, abstract = {Thermoelectric materials are engines that convert heat into an electrical current. Intuitively, the efficiency of this process depends on how many electrons (charge carriers) can move and how easily they do so, how much energy those moving electrons transport, and how easily the temperature gradient is maintained. In terms of material properties, an excellent thermoelectric material requires a high electrical conductivity σ, a high Seebeck coefficient S (a measure of the induced thermoelectric voltage as a function of temperature gradient), and a low thermal conductivity κ. The challenge is that these three properties are strongly interrelated in a conflicting manner (1). On page 722 of this issue, Roychowdhury et al. (2) have found a way to partially break these ties in silver antimony telluride (AgSbTe2) with the addition of cadmium (Cd) cations, which increase the ordering in this inherently disordered thermoelectric material.}, author = {Liu, Yu and Ibáñez, Maria}, issn = {1095-9203}, journal = {Science}, keywords = {multidisciplinary}, number = {6530}, pages = {678--679}, publisher = {American Association for the Advancement of Science}, title = {{Tidying up the mess}}, doi = {10.1126/science.abg0886}, volume = {371}, year = {2021}, }