Electronic Resource
Nanostructured potential well/barrier engineering for realizing unprecedentedly large thermoelectric power factors
| العنوان: | Nanostructured potential well/barrier engineering for realizing unprecedentedly large thermoelectric power factors |
|---|---|
| المؤلفون: | Neophytou, N, Foster, S, Vargiamidis, V, Pennelli, G, Narducci, D, N. Neophytou, S. Foster, V. Vargiamidis, G. Pennelli, D. Narducci |
| بيانات النشر: | Elsevier Ltd 2019 |
| نوع الوثيقة: | Electronic Resource |
| مستخلص: | This work describes, through the semi-classical Boltzmann transport theory and simulation, a novel nanostructured material design that can lead to unprecedentedly high thermoelectric power factors, with improvements of more than an order of magnitude compared to optimal bulk material power factors. The design is based on a specific grain/grain-boundary (potential well/barrier) engineering such that: i) carrier energy filtering is achieved using potential barriers, combined with ii) higher than usual doping operating conditions such that high carrier velocities and mean-free-paths are utilized, iii) minimal carrier energy relaxation is achieved after passing over the barriers to propagate the high Seebeck coefficient of the barriers into the potential wells, and, importantly, iv) an intermediate dopant-free (depleted) region is formed. Thus, the design consists of a ‘three-region geometry’, in which the high doping resides in the center/core of the potential well, with a dopant-depleted region separating the doped region from the potential barriers. It is shown that the filtering barriers are optimal when they mitigate the reduction in conductivity they introduce, and this can be done primarily when they are ‘clean’ from dopants during the process of filtering. The potential wells, on the other hand, are optimal when they mitigate the reduced Seebeck coefficient they introduce by: i) not allowing carrier energy relaxation, and ii) mitigating the reduction in mobility that the high concentration of dopant impurities causes. It is shown that dopant segregation, with ‘clean’ dopant-depletion regions around the potential barriers, serves this key purpose of improved mobility toward the phonon-limited mobility levels in the wells. Using quantum transport simulations based on the non-equilibrium Green's function method as well as semi-classical Monte Carlo simulations, we also verify the important ingredients and validate this ‘clean-filtering’ design. |
| مصطلحات الفهرس: | Energy filtering, Modulation doping, Nanocrystalline material, Seebeck coefficient, Thermoelectricity, Thermoelectricity, Nanocrystalline materials, Seebeck coefficient, Energy filtering, Modulation doping, CHIM/02 - CHIMICA FISICA, FIS/03 - FISICA DELLA MATERIA, info:eu-repo/semantics/article |
| URL: | info:eu-repo/semantics/altIdentifier/wos/WOS:000511432700006 volume:11 numberofpages:16 journal:MATERIALS TODAY PHYSICS |
| الاتاحة: | Open access content. Open access content info:eu-repo/semantics/openAccess |
| ملاحظة: | ELETTRONICO English |
| Other Numbers: | ITBAO oai:boa.unimib.it:10281/264118 10.1016/j.mtphys.2019.100159 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85077141547 1308932887 |
| المصدر المساهم: | BICOCCA OPEN ARCH From OAIster®, provided by the OCLC Cooperative. |
| رقم الانضمام: | edsoai.on1308932887 |
| قاعدة البيانات: | OAIster |
| الوصف غير متاح. |