METHOD OF SWITCHING HIGH-TEMPERATURE THERMOELEMENTS Russian patent published in 2024 - IPC H10N10/01 

FIELD: thermoelectric instrument making.

SUBSTANCE: invention relates to thermoelectric instrument making and can be used for switching sections made from different thermoelectric materials (TEM), in composite multi-section high-temperature thermoelements used in thermoelectric generators. Disclosed is a method of switching high-temperature thermoelements, the branches of which consist of several sections, one of which is made from TEM based on SiGe, the other from TEM based on PbTe or GeTe, using a Ni-In compound. Prior to application of metal contact layers, surfaces of TEM sections are subjected to mechanical treatment to roughness not exceeding thickness of formed layers, then chemical treatment of surface is carried out, for PbTe in 30 % solution of HNO₃ and for SiGe in 5 % solution of NH₄HF₂ at room temperature, for GeTe in 30 % NaOH at temperature of 45–60 °C. Barrier layers of Mo are applied on treated surfaces of TEM sections by magnetron sputtering with thickness of 200–300 nm, then Ni layers are deposited by chemical deposition in composition of Ni-P compound from solution NiCl₂×6H₂O 23 g/l; NaH₂PO₂ 35 g/l; NH₄Cl 50 g/l; NH₄OH 50 ml/l; Na₃C₆H₅O₇ 96 g/l; NaNO₃ 0.05 g/l at pH 8–9 and temperature 80–90 °C, after which an In layer is deposited on one of the sections by magnetron sputtering, wherein the ratio of the thicknesses of the deposited layers of Ni-P and In should be 20÷120 to 1, after which bonding of sections with applied layers is carried out at pressure of 9.0–11.0 MPa and temperature of 550–600 °C to form a solid solution of In-Ni. Proposed method enables to obtain mechanically strong, thermostable switching connections of sections made from SiGe, PbTe and GeTe in a high-temperature multisectional thermoelement.

EFFECT: compounds have temporary thermal stability at temperatures up to 900 °C, while maintaining low values of specific resistance, specific contact resistance, and high adhesion strength.

1 cl, 3 dwg