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arXiv · 2001.09708

Metal to insulator transition, colossal Seebeck coefficient and ultralow thermal conductivity in solution-processed monodispersed nickel nanoparticles

Vikash Sharma·Gunadhor Singh Okram·Yung-Kang Kuo
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Abstract

We report here metal to insulator transition, colossal Seebeck coefficient and ultralow thermal conductivity (0.0057th of its bulk value, significantly smaller than many well-known thermoelectric materials and silicon, showing potential applications in thermoelectrics, electronics and photonics for heat dissipation) in monodispersed well characterized Ni nanoparticles. As a consequence, thermoelectric power factor and figure of merit are significantly enhanced compared to their bulk counterpart. Interestingly, a systematic crossover from metallic to semiconducting to finally electrically insulating behavior, large negative temperature coefficient of resistance and n-type conduction to p-type conduction with decrease in particle size have been observed. These results are mainly attributed to formation of metal/organic interfaces, enhancement in local electronic density of sates and multiscale electron and phonon scattering by various defects. Thus, this study will open a new avenue to make better thermoelectrics through incorporation of such nanoparticles in semiconducting hosts.

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Vikash Sharma, Gunadhor Singh Okram, Yung-Kang Kuo. 2020-01-27. Metal to insulator transition, colossal Seebeck coefficient and ultralow thermal conductivity in solution-processed monodispersed nickel nanoparticles. https://arxiv.org/abs/2001.09708

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