Bridging silicon nanoparticles and thermoelectrics: phenylacetylene functionalization

Abstract

Silicon is a promising alternative to current thermoelectric materials (Bi2Te3). Silicon nanoparticle based materials show especially low thermal conductivities due to their high number of interfaces, which increases the observed phonon scattering. The major obstacle with these materials is maintaining high electrical conductivity. Surface functionalization with phenylacetylene shows an electrical conductivity of 18.1 S m−1 and Seebeck coefficient of 3228.8 μV K−1 as well as maintaining a thermal conductivity of 0.1 W K−1 m−1. This gives a ZT of 0.6 at 300 K which is significant for a bulk silicon based material and is similar to that of other thermoelectric materials such as Mg2Si, PbTe and SiGe alloys

Hybrid Silicon Nanostructures with Conductive Ligands and Their Microscopic Conductivity

“…1 The results show the ZT at a value of 0.6 ± 0.1 with electrical conductivity of 18.1 ± 0.1 S m À1 .…”

“…12 These spectra are in agreement with the previous results measured on the phenylacetylene-capped SiNPs. 1 The ALC resonances that are observed are around 2.2 T for both the compound and the nanoparticle samples (see Fig. 4).…”

“…1 Conjugated polymers have become attractive materials for producing thermoelectric devices. 2 Their flexibility and transparency are well suited to applications in wearable devices, along with the low working temperature range, around room temperature, rendering them superior to most traditional inorganic TE materials.…”

Nanostructured Silicon Used for Flexible and Mobile Electricity Generation

“…Silicon nanoparticles may be printed into thin films on flexible substrates for thermoelectric devices . Ashby et al anchored phenylacetylene onto a silicon‐nanoparticle surface and obtained a thermal conductivity of 0.1 W K −1 m −1 and a ZT of 0.6 at room temperature . Neophytou predicted the thermal conductivities may be reduced to 2 W m −1 K −1 and the ZT value could reach ca.…”

Gas‐Phase Plasma Synthesis of Free‐Standing Silicon Nanoparticles for Future Energy Applications

“…Already at the beginning of the research, it was understood that having a reduced thermal conductivity is not only enough, but improving the electrical conductivity of Si is a requirement to achieve high ZT values, at least around 1. For achieving higher electronic conductivity, doping and surface functionalization became important steps to reach higher ZT values using Si‐based nanostructures. One of the most studied system is SiGe alloy with improved ZT values of up to 1.3 (at 1775 K) for n‐type Si 0.8 Ge 0.2 .…”