A method for improving the thermoelectric properties of bismuth telluride-based pseudo-ternary thermoelectric materials by co-doping er and ag

Abstract

The invention discloses a method for improving the thermoelectric performance of a bismuth telluride-based pseudo-ternary thermoelectric material by co-doping Er and Ag. The steps are as follows: mixing elemental Bi, elemental Sb, elemental Te and elemental Se, and then adding rare earth Er and half Metal Ag, obtain a mixture, pulverize the mixture and then ball-mill to obtain pseudo-ternary Er and Ag alloy powder, and then subject the pseudo-ternary Er and Ag alloy powder to high temperature and high pressure to obtain high temperature and high pressure synthesis block, and then synthesize After the block is pulverized and heated under pressure, an n-type pseudo-ternary Er and Ag-doped thermoelectric material is obtained. Combining the high temperature and high pressure method with the pressing and sintering process solves the problems of anisotropy and poor mechanical properties of the sample; through the doping of Ag, the conduction of low-energy electrons and phonons is effectively suppressed, which is beneficial to reduce the thermal conductivity of the material rate, the optimal value of the material's power factor from 15.353 μWcm ‑1 K ‑2 increased to 27.051μWcm ‑1 K ‑2 The preparation process of the invention is simple, easy to operate, and has low requirements for preparation conditions, and can effectively reduce the production cost.

Description

technical field [0001] The invention relates to the field of thermoelectric materials, in particular to a method for improving the thermoelectric performance of a bismuth telluride-based pseudo-ternary thermoelectric material by co-doping Er and Ag. Background technique [0002] With the development of modernization, the depletion of natural gas, oil and coal and the environmental pollution caused by them always remind people of the urgency of developing green energy and protecting the environment. Energy is the fundamental driving force for the development of human society. At this stage, new energy technology cannot replace the status of traditional non-renewable energy. Improving the utilization efficiency of traditional energy and developing new renewable energy are urgent problems for mankind. [0003] Thermoelectric materials can directly convert between thermal energy and electrical energy. Devices made of thermoelectric materials have the advantages of small size, si...

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Problems solved by technology

However, because its own hexahedral structure will be split at the cleavage plane, resulting in poor mechanical properties and serious loss during processing, which not only increases the production cost of the device, but also reduces the reliability of the device operation. In addition, its thermoelectric conversion efficiency has been hovering at a low level. Therefore, improving the mechanical properties and thermoelectric figure of merit (ZT) of materials is the direction that researchers have been working hard on.

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