Traditional nanosizing methods failed to improve the performance of n-type Bi2Te3 since they simply downgrade all materials properties simultaneously. Therefore, Clemson researchers and colleagues developed a novel nanosizing method in which we first peel n-type Bi2Te3 into atomically thin-sheets (akin to graphene which is one atom thick sheet of carbon atoms) and reassemble them using a spark plasma sintering process.
The researchers found that that the above described two-step process of first separating the deck of cards into individual cards and then re-assembling them into a deck via spark plasma sintering does enable us to suitably tailor the materials properties of n-type Bi2Te3for high TE performance. In this approach, the so-called 'interfacial charged defects' are generated in the sintered n-type Bi2Te3 which not only improves its structural properties but also its thermoelectric efficiency over a wide temperature window, thus making it extremely compatible with p-type Bi2Te3 for manufacturing efficient TE devices.
The improved compatibility factor (demonstrated in this paper) is expected to open new possibilities for highly efficient TE devices. The fascinating and noteworthy element of this research is that defects, which often connote impurity and are associated with low performance or efficiency, can indeed be used to tune the properties of materials to our advantage.
Today's scientific community lacks a comprehensive understanding of defects, mainly due to the absence of methods that can controllably generate and manipulate defects. The future of this research will be aimed at developing tools to generate and study defects at a fundamental level which will in turn allow the researchers to optimize materials properties of not only TE materials but also of a new class of two-dimensional materials beyond the Nobel-winning graphene for energy generation and storage.
|Contact: Ramakrishna Podila|