Decoupling effect of electrical and thermal properties of Bi₂Te₃-polypyrrole hybrid material causing remarkable enhancement in thermoelectric performance

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>We provided a Bi<SUB>2</SUB>Te<SUB>3</SUB>-polypyrrole hybrid material, in which energy band junction and phonon scattering effects should appear at the interface of the two components. The hybrid material exhibited increases in electrical resistivity and the Seebeck coefficient due the energy band junction, thus retaining the power factor without loss, whereas showing a great reduction in thermal conductivity because of the phonon scattering at the interface. This significant decoupling of electrical and thermal properties resulted in predominant figures of merit (ZT<SUB>max</SUB> ∼1.21 at 100°C and ZT<SUB>ave</SUB> ∼1.18 at 50–150°C) among n-type Bi<SUB>2</SUB>Te<SUB>3</SUB> or Bi<SUB>2</SUB>(Te,Se)<SUB>3</SUB> materials previously reported.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We strategized to hybridize Bi<SUB>2</SUB>Te<SUB>3</SUB> with polypyrrole to obtain a bulk-phase structure. </LI> <LI> The hybrid material decoupled the electrical and thermal properties. </LI> <LI> The decoupling effect induced the excellent thermoelectric (TE) performance as below. </LI> <LI> The hybrid material recorded ZT<SUB>max</SUB> ∼1.21 at 100°C and ZT<SUB>ave</SUB> ∼1.18 at 50–150°C. </LI> <LI> The highest TE performance was achieved among n-type Bi<SUB>2</SUB>Te<SUB>3</SUB> materials ever reported. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>