Environmental-friendly thermoelectric materials

Abstract

Since decades ago, thermoelectric materials have been recognized as a potential energy conversion technology due to its ability to convert heat into electricity directly. Despite that, the low efficiency and the complexity in fabrications of thermoelectric devices restrict their applications commercially. Other than that, some thermoelectric materials such as lead telluride or bismuth telluride pose threat to the environments due to their toxicity in their substance. While the current research to obtain an environmental friendly and yet abundance thermoelectric materials to be used in large quantities are currently scarce and less interested due to the lower efficiency of the materials. In this final report, I will do a complete literature review and summarize environmental friendly thermoelectric material (silicide- based). First of all, I will introduce the basic principles of thermoelectric materials, and then followed by discussing several methods to improve the ZT value of thermoelectric materials. After that a detailed overall summary of types of silicon-based thermoelectric materials will be elaborated. Finally, conclusion and future progresses in accordance to the review will be specified.Upon reviewing the research papers, it was found that:• Current highest achievement of ZT is 3 at 550 K by PbTe quantum superlattices.• In terms of silicide based, highest experimental achievement of ZT is by double doping n-type Mg2Si0.75Sn0.25 with Al and Sb at 850 K. Peak ZT of 1.4 is achieved from significant enhancement of the carrier concentration.• Magnesium silicide, HMS and SiGe have been proven to achieve reasonable dimensionless figure of merit by doping and nanostructuring.• Other types of silicides such as FeSi2, CrSi2, ReSi1.75, CoSi and Ru2Si3 are included as potential thermoelectric materials for future industrial applications. However, not much experimental results are available in current research paper as the most results are obtained are calculated theoretically.• Future recommendation is to analyse other types of thermoelectric material such as metal oxides and organic TE materials. In general, this thesis report consists of a concise justification and description on the silicidebased environmental friendly thermoelectric materials.