Exploring the thermoelectric response of novel polymorphs of ZnO for renewable energy applications using first-principles approaches

The inexpensive, earth abundant, and non-toxic thermoelectric materials are relentlessly demanded to realize the dream of sustainable energy and overcome the energy crisis. To do so, a lot of studies are being conducted on different materials at different levels. However, the energy crisis is still a big challenge. Some polymorphs of zinc oxide (ZnO) being cheaper, non-toxic, and exhibiting good thermoelectric response at high temperatures have shown its adequate potential to play a role in sustainable energy technologies. In this study, we attempt to explore the thermoelectric response of different types of ZnO polymorphs named as sphalerite, wurtzite, CsCl, NiAs, GeP, BeO, 5-5 type versus chemical potential and temperature and the study is carried out by full-potential (FP) linearised (L) augmented plane wave (APW) plus local orbitals ( lo) (FPL(APW+lo) approach structured within density functional theory (DFT) and Boltzmann transport theory. Our obtained results of thermoelectric power factors for sphalerite, wurtzite, CsCl, NiAs, GeP, BeO, 5-5 type of the polymorphs of ZnO are recorded as 8.04 x 10(11) W/mK(2)s, 7.01 x 10(11) W/mK(2)s, 11.7 x 10(11) W/mK(2)s, 4.90 x 10(11) W/mK(2)s, 4.97 x 10(11) W/mK(2)s, 2.28 x 10(11) W/mK(2)s, and 5.31 x 10(11) W/mK(2)s respectively. Hence, the considered polymorphs of ZnO have been found to exhibiting the great potential to replace expensive, rare, and toxic thermoelectric materials.