An algorithm to reduce combinatorial search in design of invisible dopants

Electronic cloaking has been recently suggested to design invisible dopants with electronic scattering cross sections smaller than 1% of the physical cross section (πa2). Cloaking layers could be designed to coat nanoparticle dopants to minimally scatter conduction electrons and to enhance the electronic mobility. In some cases, such enhancements would result in larger thermoelectric power factors. The main difficulty is the fact that the created potential upon coating is not tunable and is determined by the band alignment of the chosen materials for the core, the shell and the host as well as the charge distribution in these layers. To find proper combinations of materials, one needs to probe a large class of materials combinations and layer sizes. This approach is time-consuming and impractical. Here we introduce a mapping method to identify possible combinations by comparing the dimensionless parameters of the chosen materials with the provided maps and without any transport calculations. Using this “dimensionless mapping” approach, we have identified several combinations of core, shell and host materials for which electronic cloaking is achievable. We have optimized the size and doping level of some of these materials combinations to maximize their thermoelectric power factor. Compared to traditional impurity-doped samples, up to 14.50 times improvement in the thermoelectric power factor was observed at T = 77 K.

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