Structure Design And Performance Optimization Of Bismuth Telluride-based Thermoelectric Device

Bismuth telluride material is one of the earliest discovered semiconductor thermoelectric materials,with excellent thermoelectric properties around room temperature.Bismuth telluride-based thermoelectric devices are of great significance in the application of thermoelectricity.Bismuth telluride refrigeration devices are currently the only commercially available thermoelectric devices with high commercial value.In recent years,with the popularization of 5G technology concepts and the continuous advancement of electronic technology,especially in the chip industry,the thermal management issues have provided a new opportunity for the development of thermoelectric refrigeration.Bismuth telluride power generation devices have great application prospects in the field of low-temperature waste heat recovery.However,there are still some problems in bismuth telluride-based thermoelectric devices.In terms of commercial refrigeration devices,the related structural design is still too simplified,rough,and lacks optimized design for specific working conditions.In terms of power generation devices,there is still a lack of a truly suitable high-temperature barrier material.The influence of the mechanical properties of materials in the manufacturing process of devices,especially micro devices,needs to be considered.In this paper,we will take bismuth telluride-based thermoelectric devices as the research goal,and conduct structural design,barrier layer design,and material research to finally optimize the device performance.The main results achieved are as follows:1、A three-dimensional multi-physics model of thermoelectric refrigeration devices was established,and the influence of device structure,arrangement,insulating substrate,and service conditions on device performance was studied.Without changing the overall size of the device and the operating current,through optimization of the device structure,double optimization of cooling capacity and cooling efficiency is achieved.2、The diffusion barrier layer Fe suitable for P-type bismuth telluride material was selected by powder co-sintering.The initial interface resistivity of Fe/bismuth telluride was less than 1μΩ?cm~2.After aging at 350℃for 16 days,the interface resistivity was less than 10μΩ?cm~2,better than that of the Ni barrier used in current commercial devices.3、The raw material crushing and classification combined with SPS sintering method is used to prepare the bismuth telluride material,its thermoelectric performance is improved compared with the traditional zone melting prepared bismuth telluride material.