9 documents found, page 1 of 1
Large-scale colloidal synthesis of chalcogenides for thermoelectric applications
Sousa, Viviana; Sarkar, Arka; Lebedev, Oleg I; Candolfi, Christophe; Lenoir, Bertrand; Coelho, Rodrigo; Gonçalves, António P; Vieira, E. M. FA simple and effective preparation of solution-processed chalcogenide thermoelectric materials is described. First, PbTe, PbSe, and SnSe were prepared by gram-scale colloidal synthesis relying on the reaction between metal acetates and diphenyl dichalcogenides in hexadecylamine solvent. The resultant phase-pure chalcogenides consist of highly crystalline and defect-free particles with distinct cubic-, tetrapod-...
High Seebeck coefficient from screen-printed colloidal PbSe nanocrystals thin film
Sousa, Viviana; Savelli, Guillaume; Lebedev, Oleg I.; Kovnir, Kirill; Correia, J. H.; Vieira, E. M. F; Alpuim, Pedro; Kolen’ko, Yury V.Thin-film thermoelectrics (TEs) with a thickness of a few microns present an attractive opportunity to power the internet of things (IoT). Here, we propose screen printing as an industry-relevant technology to fabricate TE thin films from colloidal PbSe quantum dots (QDs). Monodisperse 13 nm-sized PbSe QDs with spherical morphology were synthesized through a straightforward heating-up method. The cubic-phase Pb...
Compositional fluctuations mediated by excess tellurium in bismuth antimony tel...
Chauhan, Nagendra S.; Pyrlin, Sergey V.; Lebedev, Oleg I.; Marques, L.; Ramos, Marta M. D.; Maiti, Tanmoy; Kovnir, Kirill; Korgel, Brian A.A high thermoelectric figure of merit (ZT) in state-of-the-art bismuth antimony telluride (BST) composites was attained by an excess tellurium-assisted liquid-phase compaction approach. Herein, we report a maximum ZT of approximate to 1.4 at 500 K attained for BST bulk nanocomposites fabricated by spark plasma sintering of colloidally synthesized (Bi,Sb)(2)Te-3 platelets and Te-rich rods. The Terich nanodomains...
Large-scale synthesis of semiconducting Cu(In,Ga)Se2 nanoparticles for screen p...
Gonçalves, Bruna Ferreira; LaGrow, Alec P.; Pyrlin, Sergey; Owens-Baird, Bryan; Botelho, Gabriela; Marques, L.; Ramos, Marta M. D.; Kovnir, KirillDuring the last few decades, the interest over chalcopyrite and related photovoltaics has been growing due the outstanding structural and electrical properties of the thin-film Cu(In,Ga)Se<sub>2</sub> photoabsorber. More recently, thin film deposition through solution processing has gained increasing attention from the industry, due to the potential low-cost and high-throughput production. To this end, the elim...
Scalable colloidal synthesis of Bi<inf>2</inf>Te<inf>2.7</inf>Se<inf>0.3</inf>p...
Chauhan, Nagendra S.; Lebedev, Oleg I.; Kovnir, Kirill; Pyrlin, Sergey V.; Marques, L.; Ramos, Marta M. D.; Korgel, Brian A.; Kolen'Ko, Yury V.Colloidal synthesis is harnessed for the gram-scale preparation of hexagonal-shaped plate-like Bi2Te2.7Se0.3 particles, yielding nearly 5 g of the product in one experiment. The resultant textured particles are highly crystalline, phase-pure, chemically uniform, and can serve as a starting material for the preparation of bulk thermoelectrics for room temperature applications. The consolidation occurs via spark ...
Superstructural ordering in hexagonal CuInSe2 nanoparticles
Sousa, Viviana; Gonçalves, Bruna F.; Franco, Miguel; Ziouani, Yasmine; González-Ballesteros, Noelia; Cerqueira, M. F.; Yannello, Vincent; Kovnir, KirillChalcogenide semiconducting nanoparticles are promising building blocks for solution-processed fabrication of optoelectronic devices. In this work, we report a new large-scale colloidal synthesis of metastable CuInSe2 nanoparticles with hexagonal plate-like morphology. Powder X-ray diffraction analysis of the nanoparticles showed that the structure of the nanoparticles is not simple hexagonal wurtzite-type CuIn...
Probing of thermal transport in 50 nm thick PbTe nanocrystal films by time-doma...
Piotrowski, Marek; Franco, Miguel; Sousa, Viviana; Rodrigues, José; Deepak, Francis Leonard; Kakefuda, Yohei; Kawamoto, Naoyuki; Baba, TetsuyaBottom-up fabrication of thermoelectric (TE) materials from colloidal nanocrystal (NC) building blocks can substantially increase their TE efficiency, for example, by reducing lattice thermal conductivity. In this work, 10 nm spherical phase pure oleate-capped PbTe NCs with narrow size distribution were synthesized and employed to fabricate 50 nm thick films on insulating SiO2/Si substrates. The spin-coating, w...
Electrocatalytic performance and stability of nanostructured Fe–Ni pyrite-type ...
Costa, José Diogo; Lado, José Luis; Carbó-Argibay, Enrique; Paz, Elvira; Gallo, Juan; Cerqueira, M. F.; Rodríguez-Abreu, Carlos; Kovnir, KirillA simple and effective method to prepare an active and stable nanostructured working electrode for electrochemical water splitting is described. Specifically, mixed Fe–Ni diphosphide was prepared by sputtering a 200-nm-thick layer of Permalloy onto carbon paper gas diffusion layer followed by gas transport phosphorization reaction. The mass density of the resultant diphosphide phase was established to be 1.1 m...
A systematic study of the structural and magnetic properties of Mn-, Co-, and N...
Kolen’ko, Yury V.; Bañobre-López, Manuel; Deepak, Francis Leonard; Carbó-Argibay, Enrique; Rodríguez-Abreu, Carlos; Cerqueira, M. F.A series of colloidal MxFe3-xO4 (M = Mn, Co, Ni; x = 0–1) nanoparticles with diameters ranging from 6.8 to 11.6 nm was synthesized by hydrothermal reaction in aqueous medium at low temperature (200 °C). Energy-dispersive X-ray microa-nalysis and inductively coupled plasma spectrometry confirms that the actual elemental compositions agree well with the nominal ones. The structural properties of obtained nanopart...