TY  - JOUR
A1  - Mazzio, Katherine A.
A1  - Kojda, Sandrino Danny
A1  - Rubio-Govea, Rodrigo
A1  - Niederhausen, Jens
A1  - Ryll, Britta
A1  - Raja-Thulasimani, Monika
A1  - Habicht, Klaus
A1  - Raoux, Simone
T1  - P-type-to-n-type transition in hybrid AgxTe/PEDOT:PSS thermoelectric materials via stoichiometric control during solution-based synthesis
JF  - ACS applied energy materials
N2  - This work demonstrates the production of high-performing p- type and n-type hybrid AgxTe/poly(3,4-ethylenedioxythiopene):polystyrene sulfonic acid (PE-DOT:PSS) thermoelectric materials from the same Te/PEDOT:PSS parent structure during aqueous-based synthesis. All samples were solution-processed and analyzed in thin- film architectures. We were able to demonstrate a power factor of 44 mu W m(-1) K-2 for our highest-performing n-type material. In addition, we were also able to realize a 68% improvement in the power factor of our p-type compositions relative to the parent structure through manipulation of the inorganic nanostructure composition. We demonstrate control over the thermoelectric properties by varying the stoichiometry of AgxTe nanoparticles in AgxTe/PEDOT:PSS hybrid materials via a topotactic chemical transformation process at room temperature. This process offers a simple, low-temperature, and cost-effective route toward the production of both efficient n-type and p-type hybrid thermoelectric materials.
KW  - thermoelectrics
KW  - hybrid material
KW  - PEDOT:PSS
KW  - tellurium
KW  - silver
KW  - telluride
KW  - hybrid synthesis
Y1  - 2020
U6  - https://doi.org/10.1021/acsaem.0c01774
SN  - 2574-0962
VL  - 3
IS  - 11
SP  - 10734
EP  - 10743
PB  - ACS Publications
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Ryll, Britta
A1  - Schmitz, Andreas
A1  - de Boor, Johannes
A1  - Franz, Alexandra
A1  - Whitfield, Pamela S.
A1  - Reehuis, Manfred
A1  - Hoser, Andreas
A1  - Müller, Eckhard
A1  - Habicht, Klaus
A1  - Fritscht, Katharina
T1  - Structure, phase composition, and thermoelectric properties of YbxCo4Sb12 and their dependence on synthesis method
JF  - ACS applied energy materials
N2  - We present a combined microscopic and macroscopic study of YbxCo4Sb12 skutterudites for a range of nominal filling fractions, 0.15 < x < 0.75. The samples were synthesized using two different methods — a melt–quench–annealing route in evacuated quartz ampoules and a non-equilibrium ball-mill route — for which we directly compare the crystal structure and phase composition as well as the thermoelectric properties. Rietveld refinements of high-quality neutron powder diffraction data reveal about a 30–40% smaller Yb occupancy on the crystallographic 2a site than nominally expected for both synthesis routes. We observe a maximum filling fraction of at least 0.439(7) for a sample synthesized by the ball-mill routine, exceeding theoretical predictions of the filling fraction limit of 0.2–0.3. A single secondary phase of CoSb2 is observed in ball-mill-synthesized samples, while two secondary phases, CoSb2 and YbSb2, are detected for samples prepared by the ampoule route. A detrimental influence of the secondary phases on the thermoelectric properties is observed for secondary-phase fractions larger than 8 wt % regardless of the kind of secondary phase. The largest figure of merit of all samples with a ZT ∼ 1.0 at 723 K is observed for the sample with a refined Yb content of x2a = 0.159(3), synthesized by the ampoule route.
KW  - thermoelectric materials
KW  - skutterudite
KW  - melt-quench-anneal
KW  - ball mill
KW  - neutron powder diffraction
KW  - thermoelectric properties
KW  - figure of merit
Y1  - 2017
U6  - https://doi.org/10.1021/acsaem.7b00015
SN  - 2574-0962
VL  - 1
IS  - 1
SP  - 113
EP  - 122
PB  - American Chemical Society
CY  - Washington
ER  -