Thermal transport properties of boron nitride based materials: A review

The era of thermoelectric materials has begun in the search of clean, green and renewable anticipated energy resources. Thermoelectric materials are attracting a lot of spotlights by directly converting waste heat in electricity and could be a valuable part in world's energy emergence. Present review provides an insight into the emerging boron nitride (BN) structures on the basis of their thermoelectric properties. In the recent years, advances in the synthesis of boron nitride based structures which are analogous to carbon, have attracted significant interest by the researchers. The electronic, optical and vibrational properties of boron nitride structures are widely studied, while the thermoelectric properties have not been thoroughly investigated. However, over the past years, a significant effort has been directed towards the enhancement of their thermoelectric properties. The higher the value of figure of merit (ZT), the greater is the production of electricity. Different technologies were adopted by researchers in developing the thermoelectric efficiency. Due to the interconnection between thermoelectric parameters it is difficult to achieve ZT up to 2 or 3. Commercially existing Pb–Te and Bi–Te based thermoelectric materials provide good thermoelectric efficiency but are toxic, denser and of high cost. Therefore, there is a need of environment friendly, reusable and low cost thermoelectric materials. An extensive review of the thermoelectric characteristics of bulk phases of BN (like a-BN, c-BN, and w-BN), hexagonal-BN (h-BN), boron nitride nanotube (BNNT), boron nitride nanoribbon (ABNNR and ZBNNR), boron nitride quantum dots and boron nitride composites is presented. This evolution in boron nitride based materials will elucidate their potential for developing high-performance next-generation thermoelectric devices.