Thermoelectric properties of In and I doped PbTe

Abstract

A systematic study of structural, microstructural, and thermoelectric properties of bulk PbTe doped with indium (In) alone and co-doped with both indium and iodine (I) has been done. X-ray diffraction results showed all the samples to be of single phase. Scanning electron microscopy (SEM) results revealed the particle sizes to be in the range of micrometers, while high resolution transmission electron microscopy was used to investigate distinct microstructural features such as interfaces, grain boundaries, and strain field domains. Hall measurement at 300 K revealed the carrier concentration $10 19 cm À3 showing the degenerate nature which was further seen in the electrical resistivity of samples, which increased with rising temperature. Seebeck coefficient indicated that all samples were n-type semiconductors with electrons as the majority carriers throughout the temperature range. A maximum power factor $25 lW cm À1 K À2 for all In doped samples and Pb 0.998 In 0.003 Te 1.000 I 0.003 was observed at 700 K. Doping leads to a reduction in the total thermal conductivity due to enhanced phonon scattering by mass fluctuations and distinct microstructure features such as interfaces, grain boundaries, and strain field domains. The highest zT of 1.12 at 773 K for In doped samples and a zT of 1.1 at 770 K for In and I co-doped samples were obtained.

From Dislocation to Nano‐Precipitation: Evolution to Low Thermal Conductivity and High Thermoelectric Performance in n‐Type PbTe

“…The x = ℏω / k B T contains the angular frequency ω. The τ total is the total relaxation time that comprises the scattering of the normal (N process, τ N ), the Umklapp phonon–phonon (U process, τ U ), the point defect (PD) (τ P ), [ 65,66 ] the interface (I) (τ I ), [ 67 ] the dislocation core (DC) (τ DC ), [ 68 ] and the dislocation strain field (DS) (τ DS ) [ 69 ] via the relation: …”

“…For decades, the conversion efficiency of lead tellurides with dopants has steadily improved alongside the development of mid‐temperature TE generators. [ 4–8 ] Through the carrier optimization [ 9–12 ] and the all‐scale microstructure engineering, [ 13–19 ] the zT values for both p ‐type and n ‐type lead tellurides are enhanced. Recently, the thermodynamic routes emerged [ 20 ] as new paradigms to hunt for the low‐κ and high‐ zT TE alloys, in which their TE performance is correlated with the mutual solubilities of constituent elements, the microstructure, and the phase stability.…”

Influence of Deformation on Pb1−xInxTe1−yIy and Pb1−x−ySnxInyTe Films

“…In the following years, the study of indium in PbTe and its alloys was further developed in experimental and theoretical works. [21][22][23][24][25][26][27][28][29][30][31] DOI: 10.1002/pssb.202000304 Herein, the original technique for transport measurements at one-axis deformation is applied for the characterization of In-doped n-type Pb 1Àx Sn x Te thin films on a mica substrate. The main advantage of the developed setup is the possibility of obtaining a significantly higher pressure compared with bulk samples.…”

“…In the following years, the study of indium in PbTe and its alloys was further developed in experimental and theoretical works. [ 21–31 ] Stabilization (pinning effect) of chemical potential at the level corresponding to quasi‐local states inside the conduction band was observed for different amounts of In at low temperature. As the temperature increases, the impurity level moves into the forbidden band, and as the hydrostatic pressure increases, it moves in the opposite direction.…”

Enhancement in thermoelectric performance of n-type Pb-deficit Pb-Sb-Te alloys

“…Advances in recent times show that it is feasible to enhance zT by a number of approaches [1][2][3][4]. One approach is solid solution alloying, which enables acoustic phonon scattering leading to a decreased latt [5][6][7][8][9][10].…”