Performance Optimization of Thermoelectric Devices and its Dependence on Materials Properties

Abstract

In this perspective, we discuss the optimized performance of thermoelectric cooling devices and how it is affected by materials properties. The discussion is based on simulations using a numerical method with one dimensional transport equations and the concept of relative current density. The coefficient of performance (COP), representing the efficiency of a device, is of key importance such that when designing a new type of device, it is the parameter to be maximized, whereas others such as the cooling power, can be set by adjusting the dimensions of the design. The COP of a single stage device under a given temperature difference, is only determined by the materials’ figure of merit zT (or z) and the Seebeck coefficient . While it is the higher the better for the former, the influence of  is complicated. While higher zTs are always preferred, materials with comparably high zT and very different  could be valuable in constructing graded legs that outperform uniform ones. Lastly, proper pairing of legs is important to ensure the materials properties are used to their full potential.

Lattice plainification advances highly effective SnSe crystalline thermoelectrics

“…S20B). We believe that the gap between theoretical and experimental ∆ T max values can be further narrowed by optimizing the interfacial contacting structure and the size of thermoelectric particles in the device ( 49 , 50 ). Therefore, much higher performance in both thermoelectric power generation and Peltier cooling are expected through future optimizing of the contact resistance and shape factor, which are believed to be the critical factors that determine the performance of thermoelectric devices.…”

Grid-plainification enables medium-temperature PbSe thermoelectrics to cool better than Bi 2 Te 3

“…We have pointed out that carrier mobility is crucial for enhancing the electrical performance of thermoelectrics near room temperature to achieve better cooling capability ( 5 , 40 ). Moreover, optimal carrier mobility is beneficial for high electrical conductivity and low internal resistance in thermoelectrics, which contribute to reducing the operating power consumption of cooling devices ( 41 ). The grid-plainification strategy of using composition-process control ( 5 ) through introducing extra Pb in PbSe boosts the carrier mobility and power factor not only near room temperature but also over the entire temperature measurement range.…”

Electrical and Thermal Transport Properties of Ge1–xPbxCuySbyTeSe2y

“…[4][5][6][7] The superior TE performance demands the integration of excellent power factor (PF = S 2 𝜎) and low 𝜅, which acts as a guide for seeking novel TE materials. [8][9][10][11] Effective means of modifying band structure, adjusting carrier density (n H ), and boosting carrier mobility (μ H ) are established to promote the power factor. [3,6,12,13] Simultaneously, modulating lattice structure, resonant bonding, and exploring intrinsically low 𝜅 materials are implemented to strongly intensify phonons scattering.…”