Thermoelectric performance of biased silicene nanoribbon in the presence of magnetic field

Abstract

In this study with the tight binding model, we investigated the electronic and thermal properties of biased Armchair Silicene nanoribbon (AN-SiNR) in the presence of the perpendicular magnetic field. The band gap of AN-SiNRs decreases and increases with applying the vertical magnetic field and bias voltage, respectively. In the presence of magnetic field the DOS spectrum shows significant modifications such as splitting the DOS peak and changing the number of DOS peaks. The thermal properties of unbiased A16-SiNR in absence of external fields is negligible in low temperature and increases rapidly with temperature because the thermal energy increases with T. The bias voltage and magnetic field have opposite effects on the electronic and thermal properties of SiNRs. The increasing rate of thermal properties in terms of temperature decreases (increases) with bias voltage U (magnetic field Π) and the stronger U (Π) has smaller (larger) thermal properties due to increasing (decreasing) the band gap. The Lorenz coefficient has peak for each AN-SiNRs and it decreases by increasing the magnetic field and their peak positions move to lower temperature range. By comparing the thermal properties of A16-SiNR and A19-SiNR, we found that A19-SiNR has higher thermal properties because it has a smaller band gap in the present magnetic field and bias voltage and its charge carriers can be excited to conduction bands by lower thermal energy.