جستجوی مقالات مرتبط با کلیدواژه « nanotube » در نشریات گروه « فیزیک »

In this study, the thermoelectric properties of (6, 0) two sided-closed single-walled boron nitride nanotube ((6, 0) TSC-SWBNNT) in the state without impurity and a single carbon atom impurity instead of boron and nitrogen atoms in the center, left and right The nanotube was investigated in the energy range of -5.5 to 5.5 eV and temperatures of 200, 300, 500, 700, 900, 1100 and 1300 K. The results show that, with the increase in temperature and the creation of impurity, the band gap is affected and becomes noticeably smaller. The highest decrease in band gap is at 1300 K. With increasing temperature, the number of peaks has decreased, which shows that the mobility of electrons and holes has increased and their localization has decreased. As the temperature increases, the height of the thermal conduction peaks increases. But in general, the thermal conduction values are in the range of 9-10 nanoscale. Merit coefficient (ZT) values have increased with the increase in temperature, and the highest values are related to the temperature of 1300 K. The high values of 1 for ZT especially at high temperatures indicates that (6, 0) TSC-SWBNNT are suitable for choosing as thermoelectric material.

In this study, thermoelectric properties of the two sided-closed single-walled boron nitride nanotubes (TSC-SWBNNTs) are investigated. For this purpose, a nanotube with the chirality of (6, 3) is selected with no impurities. The energy is considered in the range of -5.5 to 5.5 electron volts and the investigations are performed at the temperatures 300, 500, 700 and 900K. The results show that increasing temperature results in significant reduction in the length of the bandgap. Besides, the peaks of the conduction diagram become smaller and their number decreases, indicating the return of more electrons and holes around the LUMO and HOMO bands, respectively, which leads to reduction of the bandgap and increase in the conduction. Moreover, the seebeck coefficient (thermal power) has increased to about 370 μV/K by increasing temperature to 900K. As the temperature increases, the coefficient of merit (ZT) increases to about 0.95, and it is expected to experience more increase with further increase in temperature. Thermal conductivity has also increased slightly with increasing temperature. However, the values of thermal conductivity are at the nanoscale. Therefore, in general, it can be concluded that the (TSC-SWBNNT) (6, 3) can be selected as a suitable thermoelectric material.