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Item type:Publication, Dual optimization of ZT and output power in bulk Bi2Te3 through metal-assisted chemical etching(2026-03-01); ; Nguyen, Duc NamThermoelectric materials offer a promising route for sustainable energy harvesting by directly converting waste heat into electricity, enabling compact, solid-state, and environmentally friendly energy solutions. Among them, bismuth telluride (Bi₂Te₃) stands out as the benchmark material for near-room-temperature applications due to its excellent electronic transport properties and commercial maturity. However, achieving high-performance in bulk or thick-film Bi₂Te₃ remains a formidable challenge. Conventional strategies such as doping, alloying, and nanoinclusion, while successful in thin films, often fail to translate effectively to bulk systems due to issues like pore collapse, poor uniformity, and degraded electrical connectivity. These limitations hinder the formation of efficient phonon-scattering architectures without compromising charge transport, resulting in limited improvement in the thermoelectric figure of merit (ZT). In this study, we present a novel and scalable nanoengineering strategy that applies metal-assisted chemical etching (MACE) to fabricate nanoporous surface layers on bulk Bi₂Te₃ for the first time. Unlike conventional nanostructuring techniques, MACE enables the formation of oriented nanostructures via a simple wet-chemical process, offering high tunability, low cost, and compatibility with large-area substrates. To reduce interfacial resistance, nickel was subsequently electrodeposited onto the nanostructured surface, forming a conformal contact layer that improves charge extraction and output performance. By systematically tuning the MACE duration, the optimized nanostructured Bi₂Te₃ sample exhibited a 2.3-fold improvement compared to the pristine bulk sample. Furthermore, due to the increased surface area from the nanoporous architecture, the internal resistance and output power of the nanostructured Bi₂Te₃ devices demonstrated 25-fold and 5.8-fold improvments, respectively, relative to the untreated sample. These remarkable improvements are attributed to the synergistic effect of enhanced phonon scattering within the nanoporous layer and improved charge transport enabled by the conformal nickel coating. This work not only introduces a powerful nanostructuring route for Bi₂Te₃ but also establishes a practical platform for high-performance, thick-film thermoelectric devices. The findings offer deep insight into the structure, property, and performance relationships governing thermoelectric efficiency and pave the way toward the scalable fabrication of next-generation thermoelectric modules for real-world applications such as industrial waste heat recovery and self-powered electronics.2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Structural, optical and electrochemical performances of undoped and Sn2+-doped Bi2Te3 nanoparticles on WO3 electrodes(2020-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancement of fluorescence in inorganic dyes by metallic nanostructured surfaces(2016-01-01); We have studied the influence of shape and chemical content of metallic nanostructures (gold-palladium core-shell nanorods, gold nanobipyramids and single-crystalline porous palladium nanocrystals) on the luminescence of Rhodamine 6G and Coumarin153 dyes. The changes found in the emission intensity are attributed to different proportions of the dyes and the metallic nanostructures. The enhancement of the fluorescence observed by us for the cases of Rhodamine 6G with gold-palladium core-shell nanorods and Rhodamine 6G with gold nanobipyramids suggests their promising plasmonic properties. This may be regarded as a preliminary step towards development of the fluorescent probes possessing high photo-sensitivity. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of calcination temperature on structural and photocatalyst properties of nanofibers prepared from low-cost natural ilmenite mineral by simple hydrothermal method(2013-09-01)