Structural and thermoelectric properties of MoSe2/CNT nanocomposites

Abstract

Two-dimensional (2D) materials have emerged as a focus of research on energy conversion in recent years owing to their high thermal and thermoelectric efficiency. The authors of this study investigate the impact of carbon nanotubes (CNTs) on the structural, morphological, and thermoelectric properties of molybdenum diselenide (MoSe2). X-ray diffraction (XRD), Raman spectroscopy, Energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses were used to characterize the nanocomposites. The results showed that the layers of MoSe2 surrounded the CNTs and carrier transport occurred from MoSe2 to CNTs. The conductivity of the nanocomposite samples was significantly enhanced by incorporating the CNTs, which are known as mobility boosters. The thermoelectric power factor was 3.6 times higher than that of the pristine sample at ambient temperature. However, the random orientation of the CNTs in the nanocomposite at temperatures above 370 K led to high scattering at the interface that hindered the flow of current and reduced the mean free path of the carriers. Moreover, disordered grain boundaries and defects within the CNTs contributed to increased scattering at higher temperatures, and increased the power factor of the pristine MoSe2 by only 1.25 times. The results of this study demonstrated the potential of MoSe2/CNT nanocomposites for use in thermoelectric applications.