@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{10327,
  abstract     = {Composite materials offer numerous advantages in a wide range of applications, including thermoelectrics. Here, semiconductor–metal composites are produced by just blending nanoparticles of a sulfide semiconductor obtained in aqueous solution and at room temperature with a metallic Cu powder. The obtained blend is annealed in a reducing atmosphere and afterward consolidated into dense polycrystalline pellets through spark plasma sintering (SPS). We observe that, during the annealing process, the presence of metallic copper activates a partial reduction of the PbS, resulting in the formation of PbS–Pb–CuxS composites. The presence of metallic lead during the SPS process habilitates the liquid-phase sintering of the composite. Besides, by comparing the transport properties of PbS, the PbS–Pb–CuxS composites, and PbS–CuxS composites obtained by blending PbS and CuxS nanoparticles, we demonstrate that the presence of metallic lead decisively contributes to a strong increase of the charge carrier concentration through spillover of charge carriers enabled by the low work function of lead. The increase in charge carrier concentration translates into much higher electrical conductivities and moderately lower Seebeck coefficients. These properties translate into power factors up to 2.1 mW m–1 K–2 at ambient temperature, well above those of PbS and PbS + CuxS. Additionally, the presence of multiple phases in the final composite results in a notable decrease in the lattice thermal conductivity. Overall, the introduction of metallic copper in the initial blend results in a significant improvement of the thermoelectric performance of PbS, reaching a dimensionless thermoelectric figure of merit ZT = 1.1 at 750 K, which represents about a 400% increase over bare PbS. Besides, an average ZTave = 0.72 in the temperature range 320–773 K is demonstrated.},
  author       = {Li, Mengyao and Liu, Yu and Zhang, Yu and Han, Xu and Xiao, Ke and Nabahat, Mehran and Arbiol, Jordi and Llorca, Jordi and Ibáñez, Maria and Cabot, Andreu},
  issn         = {1944-8252},
  journal      = {ACS Applied Materials and Interfaces},
  keywords     = {CuxS, PbS, energy conversion, nanocomposite, nanoparticle, solution synthesis, thermoelectric},
  number       = {43},
  pages        = {51373–51382},
  publisher    = {American Chemical Society },
  title        = {{PbS–Pb–CuxS composites for thermoelectric application}},
  doi          = {10.1021/acsami.1c15609},
  volume       = {13},
  year         = {2021},
}