Preparation method of high-performance doping strontium titanate oxide thermoelectric film

Abstract

The invention discloses a preparation method of a high-performance doping strontium titanate perovskite oxide thermoelectric film. The method is characterized in that epitaxial coherent growth of a doping strontium titanate film material on the surface of an oxide monocrystal substrate which has the same lattice body structure and an unmatched parameter compared with the film material is realized by controlling a plasma property and a substrate condition; and an interfacial stress field is generated. A crystal structure property, an electronic structure property and a polarization characteristic of the film material, and an interfacial property between the film material and the substrate are adjusted by the stress field and the lattice distortion degree of the film material, so that thermoelectric transmission properties of the material such as conductivity and a seebeck coefficient are greatly improved. A room-temperature thermoelectric power factor of the prepared doping strontium titanate film material is 50-10000mnW / (cm*K<2>). The high-performance doping strontium titanate film material prepared by the method can be further applied to design and preparation of a thermoelectric device, so that the thermal and electric energy conversion efficiency of the prepared thermoelectric device during realization of functions such as temperature difference power generation, refrigeration and temperature sensing can be greatly improved.

Description

technical field [0001] The invention belongs to the field of thermoelectric conversion materials and devices and the growth of thin film materials, and in particular relates to a method for preparing a high-performance doped strontium titanate perovskite oxide thermoelectric thin film. Background technique [0002] Thermoelectric materials and devices can realize mutual conversion of thermal energy and electrical energy under all solid-state conditions through the Seebeck effect and Peltier effect. In recent years, people's research interest in thermoelectric materials has mainly focused on the following two aspects: 1) the development of new thermoelectric compounds Continuous exploration of material systems [NPG Asia Mater., 2015, 7, e210, Adv. Mater., 2015, 27, 3639, Nature, 2014, 508, 373] and new synthesis methods [Nature Communications, 2014, 5, 4908]; 2 ) Improve the performance of existing thermoelectric materials by using scale and dimension effects through microstr...

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Problems solved by technology

[0005] However, it is undeniable that there are still the following problems in the field of thermoelectricity: 1) The power factors of existing thermoelectric materials with scales above microns are mostly lower than 100 μW / (cm K 2 ); 2) The thermoelectric effect utilizes the bulk effect in the practical application of the device, and the thickness of the supercrystalline and two-dimensional electron gas structure thermoelectric thin film materials reported in the past is usually below a few nanometers, which greatly restricts the thickness of the thin film material. Practical application in the device

To sum up, there is no device in this field that can achieve a thickness of more than 100 nanometers and a thermoelectric power factor exceeding 100 μW / (cm K 2 ) high-performance thermoelectric thin film

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