Approach to improving the energy efficiency of thermoelectric coolers for IR detectors

The research is aimed at approaches to increasing the efficiency of thermoelectric coolers (TECs) for IR detectors and the development of experimental methods and tools for their implementation. One way is to optimize Bi2Te3-based materials by using inhomogeneous materials. Another way is to optimize the module design taking into account the electrical and thermal resistances of the contacts in the module, which reduce the coefficient of performance (COP). A new numerical method based on the optimal control theory is proposed for designing modules in the maximum COP mode. The results of the COP calculation prove that reducing the electrical contact resistance is the predominant factor for improving the efficiency of modules for IR detectors. The COP of coolers increases by 1.5–2.5 times compared to commercial modules if the contact resistance is brought closer to the minimum value of 10−7 Ω cm2. The use of inhomogeneous thermoelements and insulating plates made of aluminum nitride instead of alumina ceramics provides an additional increase in COP by 10% and 20%, respectively. To control the contact resistance, an improved probe method of measuring is proposed. Computer simulation is applied to estimate the uncertainty of contact resistance measuring by this method. It is proven that the uncertainty does not exceed 2%.